Add A Glossary

From f087e44fe4db7996880cf4df982297018d444363 Mon Sep 17 00:00:00 2001
From: Corey Huinker <corey.huinker@gmail.com>
Date: Wed, 12 Feb 2020 04:17:59 +0000
Subject: [PATCH] add glossary page with initial definitions

---
 doc/src/sgml/filelist.sgml |   1 +
 doc/src/sgml/glossary.sgml | 540 +++++++++++++++++++++++++++++++++++++
 doc/src/sgml/postgres.sgml |   1 +
 3 files changed, 542 insertions(+)
 create mode 100644 doc/src/sgml/glossary.sgml

diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 3da2365ea9..504c8a6326 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY glossary   SYSTEM "glossary.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..1b881690fa
--- /dev/null
+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,540 @@
+<!-- doc/src/sgml/glossary.sgml -->
+
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+  This is a list of terms and their definitions in the context of <productname>PostgreSQL</productname> and databases in general.
+ </para>
+  <glosslist>
+   <glossentry>
+    <glossterm>Aggregate</glossterm>
+    <glossdef>
+     <para>
+      The act of combining a defined collection of data values into a single value that may not be the same type as the original values. Aggregate <glossterm>functions</glossterm> are most often used with Grouping operations which define the separate sets of data by the common values shared within those sets.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Analytic</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>function</glossterm> whose computed value can reference values found in nearby <glossterm>rows</glossterm> of the same result set.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Atomic</glossterm>
+    <glossdef>
+     <para>
+      When referring to the value of an <glossterm>attribute</glossterm> or <glossterm>datum</glossterm>: cannot be broken up into smaller components.
+     </para>
+     <para>
+      When referring to an operation: An event that cannot be partially completed; it must either completely succeed or completely fail. A series of <acronym>SQL</acronym> statements can be combined into a <glossterm>transaction</glossterm>, and that transaction is described as atomic.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Attribute</glossterm>
+    <glossdef>
+     <para>
+      A typed data element found within a <glossterm>tuple</glossterm> or <glossterm>relation</glossterm> or <glossterm>table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>BYTEA</glossterm>
+    <glossdef>
+     <para>
+      A data type for storing binary data. It is roughly analogous to the <literal>BLOB</literal> data type in other database products.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Cast</glossterm>
+    <glossdef>
+     <para>
+      The act of converting of a <glossterm>datum</glossterm> from its current data type to another data type.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Check Constraint</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>constraint</glossterm> defined for a <glossterm>relation</glossterm> which restricts the values allowed in one or more <glossterm>attribute</glossterm>s. The check constraint can make reference to any attribute in the relation, but cannot reference other rows of the same relation or other relations.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Column</glossterm>
+    <glossdef>
+     <para>
+      An <glossterm>attribute</glossterm> found in a <glossterm>table</glossterm> or <glossterm>view</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Commit</glossterm>
+    <glossdef>
+     <para>
+      The act of finalizing a <glossterm>transaction</glossterm> within the database.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Concurrency</glossterm>
+    <glossdef>
+     <para>
+      The concept that multiple independent operations can be happening within the database at the same time.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Constraint</glossterm>
+    <glossdef>
+     <para>
+      A method of restricting the values of data allowed within a <glossterm>relation</glossterm>. Constraints can currently be of the following types: <glossterm>Check Constraint</glossterm>, <glossterm>Unique Constraint</glossterm>, and <glossterm>Exclusion Constraint</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Datum</glossterm>
+    <glossdef>
+     <para>
+      The internal representation of a <acronym>SQL</acronym> datatype.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Delete</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command that removes rows from a given <glossterm>table</glossterm> or <glossterm>relation</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Exclusion Constraint</glossterm>
+    <glossdef>
+     <para>
+      Exclusion constraints define both a set of <glossterm>column</glossterm>s for matching <glossterm>row</glossterm>s, and rules where values in one row would conflict with values in another.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Foreign Data Wrapper</glossterm>
+    <glossdef>
+     <para>
+      A means of representing data outside the local database so that it appears as if it were in local tables. With a Foreign Data Wrapper it is possible to define a <glossterm>Foreign Server</glossterm> and <glossterm>Foreign Tables</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Foreign Key</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>constraint</glossterm> defined on one or more columns in a <glossterm>table</glossterm> which requires the value in those <glossterm>column</glossterm>s to uniquely identify a <glossterm>row</glossterm> in the specified table.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Foreign Server</glossterm>
+    <glossdef>
+     <para>
+      A named collection of <glossterm>Foreign Table</glossterm>s which all use the same <glossterm>Foreign Data Wrapper</glossterm> and have other configured <glossterm>attribute</glossterm>s in common.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Foreign Table</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>relation</glossterm> which appears to have <glossterm>row</glossterm>s and <glossterm>column</glossterm>s like a regular <glossterm>table</glossterm>, but when queried will instead forward the request for data through its <glossterm>Foreign Data Wrapper</glossterm>, which will return results structured according to the definition of the Foreign Table.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Function</glossterm>
+    <glossdef>
+     <para>
+      Any pre-defined transformation of data. Many functions are already defined within <productname>PostgreSQL</productname> itself, but user-defined <glossterm>function</glossterm>s can be added.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Grant</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command that is used to enable <glossterm>user</glossterm>s or <glossterm>role</glossterm>s to access specific objects within the database.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Index</glossterm>
+    <glossdef>
+     <para>
+      A relation that contains data derived from a <glossterm>table</glossterm> (or a <glossterm>relation</glossterm> such as a <glossterm>materialized view</glossterm>) that stores the data in a way that makes specific values easier to retrieve.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Insert</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command used to add new data into a <glossterm>table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Join</glossterm>
+    <glossdef>
+     <para>
+      A technique used with <command>SELECT</command> statements to correlate data in one data set (usually a <glossterm>table</glossterm>) with the data set already defined up to the current point in the <command>SELECT</command> statement.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Key</glossterm>
+    <glossdef>
+     <para>
+      A means of identifying a <glossterm>row</glossterm> within a <glossterm>table</glossterm> or <glossterm>relation</glossterm> using values contained within one or more <glossterm>attribute</glossterm>s in that table.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Lock</glossterm>
+    <glossdef>
+     <para>
+      A mechanism that enables one process to perform actions on a defined <glossterm>object</glossterm> or set of <glossterm>row</glossterm>s within that object while preventing other processes from querying and/or modifying them.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Logged</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>table</glossterm> is considered logged if changes to the table are sent to the <acronym>WAL</acronym>. By default, all regular tables are logged. A table can be defined as unlogged either at creation time or via the <command>ALTER TABLE</command> command. The primary use of unlogged tables is for storing transient work data that must be shared across processes, but with a final result stored in logged tables. <glossterm>Temporary</glossterm> tables are always unlogged.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Master</glossterm>
+    <glossdef>
+     <para>
+      The server that is considered the authoritative source of information for databases that are linked via replication.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Materialized</glossterm>
+    <glossdef>
+     <para>
+     The state of being stored information rather than just a defined means of accessing the information. This term is used in <glossterm>Materialized View</glossterm>s, meaning that the data derived from the <glossterm>view</glossterm> is actually stored on disk separate from the sources of that data. When materialized is used in describing multi-step queries, it means that the data of a given step is stored (in memory, but that storage may spill over onto disk).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Materialized View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>relation</glossterm> that is defined in the same way that a <glossterm>view</glossterm> is, but it stores data in the same way that a <glossterm>table</glossterm> does. It cannot be modified via <command>INSERT</command>, <command>UPDATE</command>, or <command>DELETE</command> operations.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Null</glossterm>
+    <glossdef>
+     <para>
+      A concept of non-existence that is a central tenet of relational database theory. It represents the absence of value.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Partition</glossterm>
+    <glossdef>
+     <para>
+      A member of a collection of <glossterm>table</glossterm>s organized to act as if it were itself a single unified table. Each partition is defined to hold a specific subset of data for the partitioned table that cannot overlap with any other partition in that partitioned table. Therefore, no <glossterm>row</glossterm> of data can belong in more than one partition.
+     </para>
+     <para>
+       Partitions have a name and can be queried directly through that name, but they can also be queried implicitly by querying the name of the partitioned table.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Primary Key</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>unique</glossterm> <glossterm>index</glossterm> defined on a <glossterm>table</glossterm> or other <glossterm>relation</glossterm> that also guarantees that all of the <glossterm>attribute</glossterm>s within the <glossterm>Primary Key</glossterm> do not have null values. As the name implies, there can be only one Primary Key per table, though it is possible to have multiple unique indexes that also have no <glossterm>null</glossterm>-capable attributes.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Procedure</glossterm>
+    <glossdef>
+     <para>
+      A defined set of instructions for manipulating data within a database. Procedures can be written in a variety of programming languages. They may appear like <glossterm>function</glossterm>s but are different in that they must be invoked via the <command>CALL</command> command rather than the <command>SELECT</command> or <command>PERFORM</command> commands, and they are allowed to make transactional statements like <command>COMMIT</command> and <command>ROLLBACK</command>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Record</glossterm>
+    <glossdef>
+     <para>
+      A data structure that consists of one or more <glossterm>attribute</glossterm>s in a defined order. A record that belongs to a table or other relation is more commonly called a <glossterm>row</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Referential Integrity</glossterm>
+    <glossdef>
+     <para>
+      The means of restricting data in one <glossterm>relation</glossterm> so that it must have matching data in another relation.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Relation</glossterm>
+    <glossdef>
+     <para>
+      The generic term for all objects in a database that have a name and a list of attributes defined in a specific order. <glossterm>Table</glossterm>s, <glossterm>view</glossterm>s, <glossterm>foreign table</glossterm>s, <glossterm>materialized view</glossterm>s and <glossterm>index</glossterm>es are all Relations.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Replica</glossterm>
+    <glossdef>
+     <para>
+      A database that is paired with a <glossterm>master</glossterm> database and maintains a copy of some or all of the master database's data. The primary reasons for doing this are to allow for greater access to that data, and to maintain availability of the data in the event that the master becomes unavailable.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Revoke</glossterm>
+    <glossdef>
+     <para>
+      A command to reduce access to a named set of database objects for a named list of <glossterm>user</glossterm>s and <glossterm>role</glossterm>s.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Role</glossterm>
+    <glossdef>
+     <para>
+      A collection of access privileges for the database. Roles are themselves a privilege that can be granted to other roles. This is often done for convenience or to ensure completeness when multiple <glossterm>user</glossterm>s need the same privileges.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Rollback</glossterm>
+    <glossdef>
+     <para>
+      A command to undo all of the operations performed since the beginning of a <glossterm>transaction</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Row</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>tuple</glossterm> or <glossterm>record</glossterm> found within a <glossterm>relation</glossterm> or result set. This term is often used interchangably with Tuple and Record.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Schema</glossterm>
+    <glossdef>
+     <para>
+      A named collection of database objects organized to facilitate clarity or security. Most often used in the same way a namespace is used in programming languages. All objects belong to exactly one schema, most commonly <literal>public</literal>, the default schema.
+     </para>
+     <para>
+      More generically, the term Schema is used to mean all data descriptions (<glossterm>table</glossterm> definitions, <glossterm>constraint</glossterm>s, comments) for a given database.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Select</glossterm>
+    <glossdef>
+     <para>
+      The command used to query a database. Normally, <command>SELECT</command> commands are not expected to modify the database in any way, but it is possible that <glossterm>Functions</glossterm> invoked within the query could have side effects that do modify data.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Serializable</glossterm>
+    <glossdef>
+     <para>
+      Database <glossterm>session</glossterm>s in a <glossterm>transaction</glossterm> defined as <literal>SERIALIZABLE</literal> are unable to see changes made to the database by other sessions. In effect, the entire database appears to be frozen in time for the duration of the transaction.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Session</glossterm>
+    <glossdef>
+     <para>
+      A connection to the database. Can also be used to describe a series of commands that were issued in the life cycle of a particular connection to the database.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Table</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>tuple</glossterm>s (also known as <glossterm>row</glossterm>s or <glossterm>record</glossterm>s) having a common data structure (the same number of <glossterm>column</glossterm>s, in the same order, having the same type). A table is the most common form of relation in <productname>PostgreSQL</productname>. 
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Temporary</glossterm>
+    <glossdef>
+     <para>
+      Temporary <glossterm>table</glossterm>s are tables that exist either for the lifetime of a <glossterm>session</glossterm> or a <glossterm>transaction</glossterm>, as defined at creation time. The data in them is not visible to other sessions, and is not logged. Temporary tables are most often used to store intermediate data for a multi-step data transformation.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Transaction</glossterm>
+    <glossdef>
+     <para>
+      A combination of one or more commands that must act as a single <glossterm>atomic</glossterm> command: they all succeed or fail together, and their effects are not visible to other <glossterm>session</glossterm>s until the <glossterm>transaction</glossterm> is complete.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Trigger</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>function</glossterm> which can be defined to execute whenever a certain operation (<command>INSERT</command>, <command>UPDATE</command>, or <command>DELETE</command>) is applied to that <glossterm>relation</glossterm>. A trigger executes within the same <glossterm>transaction</glossterm> as the statement which invoked it, and if the function fails then the invoking statement also fails.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Tuple</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>attribute</glossterm>s in a fixed order. That order may be defined by the <glossterm>table</glossterm> where the Tuple is found, in which case the Tuple is often called a <glossterm>row</glossterm> or <glossterm>record</glossterm>. It may also be defined by the structure of a result set.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Unique</glossterm>
+    <glossdef>
+     <para>
+      The state of having a set of columns with no matching values in the same <glossterm>relation</glossterm>. Most often used in the concept of unique indexes.
+     </para>
+    </glossdef>
+   </glossentry>
+
+    <glossentry>
+    <glossterm>Unique Constraint</glossterm>
+    <glossdef>
+     <para>
+      A rule that defines a set of <glossterm>column</glossterm>s for which no two <glossterm>row</glossterm>s in the <glossterm>table</glossterm> can share the same set of values.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Unlogged</glossterm>
+    <glossdef>
+     <para>
+      A relation that is unlogged will not have changes reflected in the <acronym>WAL</acronym>, which would enable those changes to be duplicated on a <glossterm>replica</glossterm>, and also enables the change to survive a database crash.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Update</glossterm>
+    <glossdef>
+     <para>
+      A command used to modify <glossterm>row</glossterm>s that already exist in a specified <glossterm>table</glossterm>. It cannot create <glossterm>row</glossterm>s nor can it remove them.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>User</glossterm>
+    <glossdef>
+     <para>
+      A specific case of a <glossterm>role</glossterm> that is entitled to access (log into) the database.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>User Mapping</glossterm>
+    <glossdef>
+     <para>
+      The translation of <glossterm>user</glossterm> credentials in the local database to credentials in a remote data system defined by a <glossterm>Foreign Data Wrapper</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>relation</glossterm> that is defined by a <command>SELECT</command> statement, but has no storage of its own. Any time a query references a View, the definition of the View is substituted into the query as if the user had typed that subquery instead of the name of the View.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry>
+    <glossterm>Window Function</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>function</glossterm> similar to an <glossterm>aggregate</glossterm> in that it can derive its value from a set of <glossterm>row</glossterm>s in a result set, but still retaining the original source data.
+     </para>
+    </glossdef>
+   </glossentry>
+  </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index e59cba7997..2183e33bea 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
   &docguide;
   &limits;
   &acronyms;
+  &glossary;
 
  </part>
 
-- 
2.17.1

From 690473e51fc442c55c1744f69813795fce9d22dc Mon Sep 17 00:00:00 2001
From: coreyhuinker <corey.huinker@gmail.com>
Date: Tue, 10 Mar 2020 11:26:29 -0400
Subject: [PATCH] add glossary page

---
 doc/src/sgml/filelist.sgml |    1 +
 doc/src/sgml/glossary.sgml | 1008 ++++++++++++++++++++++++++++++++++++
 doc/src/sgml/postgres.sgml |    1 +
 3 files changed, 1010 insertions(+)
 create mode 100644 doc/src/sgml/glossary.sgml

diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 3da2365ea9..504c8a6326 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY glossary   SYSTEM "glossary.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..851e9debe6
--- /dev/null
+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,1008 @@
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+  This is a list of terms and their in the context of <productname>PostgreSQL</productname> and <glossterm>Database</glossterm>s in general.
+ </para>
+  <glosslist>
+   <glossentry id="glossary-aggregate">
+    <glossterm>Aggregate</glossterm>
+    <glossdef>
+     <para>
+      To combine a collection of data values into a single value, whose value may not be of the same type as the original values. <glossterm>Aggregate</glossterm> <glossterm>Functions</glossterm> combine multiple <glossterm>Rows</glossterm> that share a common set of values into one <glossterm>Row</glossterm>, which means that the only data visible in the values in common, and the aggregates of the non-common data.
+     </para>
+     <para>
+      For more information, see <link linkend="functions-aggregate">Aggregate Functions</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-analytic">
+    <glossterm>Analytic</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Function</glossterm> whose computed value can reference values found in nearby <glossterm>Rows</glossterm> of the same <glossterm>Result Set</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="tutorial-window">Window Functions</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-archiver">
+    <glossterm>Archiver</glossterm>
+    <glossdef>
+     <para>
+      A process that backs up <glossterm>WAL Files</glossterm> in order to reclaim space on the file system.
+     </para>
+     <para>
+      For more information, see <link linkend="continuous-archiving">Backup and Restore: Continuous Archiving and Point-in-Time Recovery (PITR)</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-atomic">
+    <glossterm>Atomic</glossterm>
+    <glossdef>
+     <para>
+      In reference to the value of an <glossterm>Attribute</glossterm> or <glossterm>Datum</glossterm>: cannot be broken up into smaller components.
+     </para>
+     <para>
+      In reference to an operation: An event that cannot be completed in part: it must either entirely succeed or entirely fail. A series of <acronym>SQL</acronym> statements can be combined into a <glossterm>Transaction</glossterm>, and that <glossterm>transaction</glossterm> is said to be <glossterm>Atomic</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-attribute">
+    <glossterm>Attribute</glossterm>
+    <glossdef>
+     <para>
+      A typed data element found within a <glossterm>Tuple</glossterm> or <glossterm>Relation</glossterm> or <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-autovacuum">
+    <glossterm>Autovacuum</glossterm>
+    <glossdef>
+     <para>
+      Processes that remove outdated <acronym>MVCC</acronym> <glossterm>Records</glossterm> of the <glossterm>Heap</glossterm> and <glossterm>Index</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="routine-vacuuming">Routine Database Maintenance Tasks: Routine Vacuuming</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-backend-process">
+    <glossterm>Backend Process</glossterm>
+    <glossdef>
+     <para>
+      Processes of an <glossterm>Instance</glossterm> which act on behalf of client <glossterm>Connections</glossterm> and handle their requests.
+     </para>
+     <para>
+      (Don't confuse this term with the similar terms <glossterm>Background Worker</glossterm> or <glossterm>Background Writer</glossterm>).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-backend-server">
+    <glossterm>Backend Server</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Instance</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-background-worker">
+    <glossterm>Background Worker</glossterm>
+    <glossdef>
+     <para>
+      Individual processes within an <glossterm>Instance</glossterm>, which run system- or user-supplied code. Typical use cases are processes which handle parts of an <acronym>SQL</acronym> query to take advantage of parallel execution on servers with multiple <acronym>CPUs</acronym>.
+    </para>
+    <para>
+     For more information, see <link linkend="bgworker">Background Worker Processes</link>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-background-writer">
+    <glossterm>Background Writer</glossterm>
+    <glossdef>
+     <para>
+      Writes continuously dirty pages from <glossterm>Shared Memory</glossterm> to the file system. It starts periodically, but works only for a short period in order to distribute
+expensive <acronym>I/O</acronym> activity over time instead of generating fewer large <acronym>I/O</acronym> peaks which could block other processes.
+     </para>
+     <para>
+      For more information, see <link linkend="runtime-config-resource">Server Configuration: Resource Consumption</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-cast">
+    <glossterm>Cast</glossterm>
+    <glossdef>
+     <para>
+      A conversion of a <glossterm>Datum</glossterm> from its current data type to another data type.
+     </para>
+    </glossdef>
+   </glossentry>
+
+ <glossentry id="glossary-catalog">
+    <glossterm>Catalog</glossterm>
+    <glossdef>
+     <para>
+      The <acronym>SQL</acronym> standard uses this standalone term to indicate what is called a
+<glossterm>Database</glossterm> in <productname>PostgreSQL</productname>'s terminology.
+     </para>
+     <para>
+      For more information, see <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-check-constraint">
+    <glossterm>Check Constraint</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Constraint</glossterm> defined on a <glossterm>Relation</glossterm> which restricts the values
+allowed in one or more <glossterm>Attributes</glossterm>. The <glossterm>Check Constraint</glossterm> can make reference to
+any <glossterm>Attribute</glossterm> in the <glossterm>Relation</glossterm>, but cannot reference other <glossterm>Rows</glossterm> of the same <glossterm>Relation</glossterm> or other <glossterm>Relations</glossterm>.
+     </para>
+    <para>
+     For more information, see <link linkend="ddl-constraints">Constraints</link>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-checkpointer">
+    <glossterm>Checkpointer</glossterm>
+    <glossdef>
+     <para>
+      A process that writes dirty pages and <glossterm>WAL Records</glossterm> to the file system and creates a special checkpoint record. This process is initiated when predefined conditions are met, such as a specified amount of time has passed, or a certain volume of records have been collected.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-cluster">
+    <glossterm>Cluster</glossterm>
+    <glossdef>
+     <para>
+      A group of <glossterm>Database</glossterm>s plus their <glossterm>Global SQL Objects</glossterm>. The <glossterm>Cluster</glossterm> is managed by exactly one <glossterm>Instance</glossterm>. A newly created <glossterm>Cluster</glossterm> will have three <glossterm>Databases</glossterm> created automatically. They are <literal>template0</literal>, <literal>template1</literal>, and <literal>postgres</literal>. It is expected that an application will create one or more additional <glossterm>Databases</glossterm> aside from these three.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-column">
+    <glossterm>Column</glossterm>
+    <glossdef>
+     <para>
+      An <glossterm>Attribute</glossterm> found in a <glossterm>Table</glossterm> or <glossterm>View</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-commit">
+    <glossterm>Commit</glossterm>
+    <glossdef>
+     <para>
+      The act of finalizing a <glossterm>Transaction</glossterm> within the <glossterm>Database</glossterm>.
+     </para>
+    <para>
+     For more information, see <link linkend="sql-commit">SQL Commands: COMMIT</link>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-concurrency">
+    <glossterm>Concurrency</glossterm>
+    <glossdef>
+     <para>
+      The concept that multiple independent operations can be happening within the <glossterm>Database</glossterm> at the same time.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-connection">
+    <glossterm>Connection</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>TCP/IP</acronym> or socket line for inter-process communication. If the two involved processes reside on different servers, <acronym>TCP/IP</acronym> must be used.  Otherwise both techniques are possible.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-constraint">
+    <glossterm>Constraint</glossterm>
+    <glossdef>
+     <para>
+      A method of restricting the values of data allowed within a <glossterm>Table</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="ddl-constraints">Constraints</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-data-area">
+    <glossterm>Data Area</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Data Directory</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-data-directory">
+    <glossterm>Data Directory</glossterm>
+    <glossdef>
+     <para>
+      The base directory on the filesystem of a <glossterm>Server</glossterm> that contains all data
+files and subdirectories associated with a <glossterm>Cluster</glossterm>. The name for this directory in configuration files is <productname>PGDATA</productname>.
+     </para>
+     <para>
+      For more information, see <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-database">
+    <glossterm>Database</glossterm>
+    <glossdef>
+     <para>
+      A named collection of <glossterm>SQL Objects</glossterm>.    
+     </para>
+     <para>
+      For more information, see <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-database-server">
+    <glossterm>Database Server</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Instance</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-datum">
+    <glossterm>Datum</glossterm>
+    <glossdef>
+     <para>
+      The internal representation of a <acronym>SQL</acronym> data type.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-delete">
+    <glossterm>Delete</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command whose purpose is to remove <glossterm>Rows</glossterm> from a given <glossterm>Table</glossterm> or <glossterm>Relation</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-delete">SQL Commands: DELETE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-file-segment">
+    <glossterm>File Segment</glossterm>
+    <glossdef>
+     <para>
+       If a <glossterm>Database</glossterm> object grows in size past a designated limit, it may be
+split into multiple physical files. These files are called <glossterm>File Segments</glossterm>.
+     </para>
+     <para>
+      (Don't confuse this term with the similar term <glossterm>WAL Segment</glossterm>).
+     </para>
+     <para>
+      For more information, see <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-data-wrapper">
+    <glossterm>Foreign Data Wrapper</glossterm>
+    <glossdef>
+     <para>
+      A means of representing data that is not contained in the local <glossterm>Database</glossterm> as if were in local <glossterm>Table</glossterm>(s). With a Foreign Data Wrapper it is possible to define a <glossterm>Foreign Server</glossterm> and <glossterm>Foreign Tables</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createforeigndatawrapper">SQL Commands: CREATE FOREIGN DATA WRAPPER</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-key">
+    <glossterm>Foreign Key</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Constraint</glossterm> defined on one or more <glossterm>Column</glossterm>s in a <glossterm>Table</glossterm> which requires the value in those <glossterm>Column</glossterm>s to uniquely identify a <glossterm>Row</glossterm> in the specified <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-server">
+    <glossterm>Foreign Server</glossterm>
+    <glossdef>
+     <para>
+      A named collection of <glossterm>Foreign Tables</glossterm> which all use the same <glossterm>Foreign Data Wrapper</glossterm> and have other configuration values in common.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createserver">SQL Commands: CREATE SERVER</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-table">
+    <glossterm>Foreign Table</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> which appears to have <glossterm>Rows</glossterm> and <glossterm>Columns</glossterm> similar to a regular <glossterm>Table</glossterm>, but will forward requests for data through its <glossterm>Foreign Data Wrapper</glossterm>, which will return <glossterm>Result Sets</glossterm> structured according to the definition of the <glossterm>Foreign Table</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createforeigntable">SQL Commands: CREATE FOREIGN TABLE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-function">
+    <glossterm>Function</glossterm>
+    <glossdef>
+     <para>
+      Any pre-defined tranformation of data. Many <glossterm>Functions</glossterm> are already defined within <productname>PostgreSQL</productname> itself, but can also be user-defined.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createfunction">SQL Commands: CREATE FUNCTION</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-global-sql-object">
+    <glossterm>Global SQL Object</glossterm>
+    <glossdef>
+     <para>
+      Not all objects belong to a certain <glossterm>Schema</glossterm>, or to their <glossterm>Database</glossterm>, or even to the complete <glossterm>Cluster</glossterm>. These are referred to as <glossterm>Global SQL Objects</glossterm>. Collations and Extensions such as <glossterm>Foreign Data Wrappers</glossterm> reside at the <glossterm>Database</glossterm> level; <glossterm>Database</glossterm> names, <glossterm>Roles</glossterm>, <glossterm>Tablespaces</glossterm>, <glossterm>Replication</glossterm> origins, and subscriptions for logical <glossterm>Replication</glossterm> at the <glossterm>Cluster</glossterm> level.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-grant">
+    <glossterm>Grant</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command that is used to enable <glossterm>Users</glossterm> or <glossterm>Roles</glossterm> to access specific objects within the <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-grant">SQL Commands: GRANT</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-heap">
+    <glossterm>Heap</glossterm>
+    <glossdef>
+     <para>
+      Contains the original values of <glossterm>Row</glossterm> attributes (i.e. the data). The <glossterm>Heap</glossterm> is realized within <glossterm>Database</glossterm> files and mirrored in <glossterm>Shared Memory</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="host">
+    <glossterm>Host</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Server</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-index">
+    <glossterm>Index</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that contains data derived from a <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> such as a <glossterm>Materialized View</glossterm>) that stores the data in a way that makes specific values easier to retrieve.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createindex">SQL Commands: CREATE INDEX</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-insert">
+    <glossterm>Insert</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command used to add new data into a <glossterm>Table</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-insert">SQL Commands: INSERT</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-instance">
+    <glossterm>Instance</glossterm>
+    <glossdef>
+     <para>
+      An <glossterm>Instance</glossterm> is a group of processes plus their common <glossterm>Shared Memory</glossterm> running on a single <glossterm>Server</glossterm>. The <glossterm>Instance</glossterm> handles all key features of a <acronym>DBMS</acronym>: read and write access to files and <glossterm>Shared Memory</glossterm>, assurance of the <acronym>ACID</acronym> paradigm, <acronym>MVCC</acronym>, <glossterm>Connections</glossterm> to client programms, backup, recovery, replication, privileges, etc.
+     </para>
+     <para>
+      An <glossterm>Instance</glossterm> manages exactly one <glossterm>Cluster</glossterm>.
+     </para>
+     <para>
+      Many <glossterm>Instances</glossterm> can run on the same server as long as they use different <acronym>IP</acronym> ports and manage different <glossterm>Cluster</glossterm>s. Different <glossterm>Instances</glossterm> on a server may use the same or different versions of <productname>PostgreSQL</productname>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-join">
+    <glossterm>Join</glossterm>
+    <glossdef>
+     <para>
+      A technique used with <command>SELECT</command> statements for correlating data in one or more <glossterm>Relations</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-key">
+    <glossterm>Key</glossterm>
+    <glossdef>
+     <para>
+      A means of identifying a <glossterm>Row</glossterm> within a <glossterm>Table</glossterm> or <glossterm>Relation</glossterm> by values contained within one or more <glossterm>Attributes</glossterm> in that <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-lock">
+    <glossterm>Lock</glossterm>
+    <glossdef>
+     <para>
+      A mechanism for one process temporarily preventing data from being manipulated by any other process.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="log-record">
+    <glossterm>Log Record</glossterm>
+     <glossdef>
+      <para>
+       See <glossterm>WAL Record</glossterm>.
+      </para>
+     </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-logged">
+    <glossterm>Logged</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Table</glossterm> is considered <glossterm>Logged</glossterm> if changes to the <glossterm>Table</glossterm> are sent to the <glossterm>WAL Log</glossterm>. By default, all regular <glossterm>Tables</glossterm> are <glossterm>Logged</glossterm>. A <glossterm>Table</glossterm> can be speficied as unlogged either at creation time or via the <command>ALTER TABLE</command> command. The primary use of unlogged <glossterm>Tables</glossterm> is for storing transient work data that must be shared across processes, but with a final result stored in logged <glossterm>Tables</glossterm>.  <glossterm>Temporary Tables</glossterm> are always unlogged.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-master">
+    <glossterm>Master</glossterm>
+    <glossdef>
+     <para>
+      When two or more <glossterm>Databases</glossterm> are linked via <glossterm>Replication</glossterm>, the <glossterm>Server</glossterm> that is considered the authoritative source of information is called the <glossterm>Master</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-materialized">
+    <glossterm>Materialized</glossterm>
+    <glossdef>
+     <para>
+      The act of storing information rather than just the means of accessing the information. This term is used in <glossterm>Materialized Views</glossterm> meaning that the data derived from the <glossterm>View</glossterm> is actually stored on disk separate from the sources of that data. When the term <glossterm>Materialized</glossterm> is used in speaking about mulit-step queries, it means that the data of a given step is stored (in memory, but that storage may spill over onto disk).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-materialized-view">
+    <glossterm>Materialized View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that is defined in the same way that a <glossterm>View</glossterm> is, but it stores
+data in the same way that a <glossterm>Table</glossterm> does. it cannot be modified via <command>INSERT</command>, <command>UPDATE</command>, or <command>DELETE</command> operations.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-creatematerializedview">SQL Commands: CREATE MATERIALIZED VIEW</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-null">
+    <glossterm>Null</glossterm>
+    <glossdef>
+     <para>
+      A concept of non-existence that is a central tenet of Relational Database Theory. It represents the absence of value.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-partition">
+    <glossterm>Partition</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Table</glossterm> that can be queried independently by its own name, but can also be queried via another <glossterm>Table</glossterm>, a partitioend <glossterm>Table</glossterm>, which is a collection of sub-<glossterm>Table</glossterm>s, each capable of holding one defined subset of information that does not overlap with any other <glossterm>Table</glossterm> in the set of <glossterm>Table</glossterm>s.
+     </para>
+     <para>
+      A defined boundary used in an <glossterm>Analytic</glossterm> <glossterm>Function</glossterm> to identify which neighboring <glossterm>Rows</glossterm> can be considered by the <glossterm>Function</glossterm> for this particular <glossterm>Row</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-postmaster">
+    <glossterm>Postmaster</glossterm>
+    <glossdef>
+     <para>
+       The very first process of an <glossterm>Instance</glossterm>. It starts the other processes and creates <glossterm>Backend Processes</glossterm> on demand.
+     </para>
+     <para>
+      For more information, see <link linkend="server-start">Server Setup and Operation: Starting the Database Server</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-primary-key">
+    <glossterm>Primary Key</glossterm>
+    <glossdef>
+     <para>
+      A special case of <glossterm>Unique Index</glossterm> defined on a <glossterm>Table</glossterm> or other <glossterm>Relation</glossterm> that also guarantees that all of the <glossterm>Attributes</glossterm> within the <glossterm>Primary Key</glossterm> do not have <glossterm>Null</glossterm> values.  As the name implies, there can be only one <glossterm>Primary Key</glossterm> per <glossterm>Table</glossterm>, though it is possible to have multiple <glossterm>Unique Indexes</glossterm> that also have no <glossterm>Null</glossterm>-capable <glossterm>Attributes</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-procedure">
+    <glossterm>Procedure</glossterm>
+    <glossdef>
+     <para>
+      A defined set of instructions for manipulating data within a <glossterm>Database</glossterm>. <glossterm>Procedure</glossterm> can be written in a variety of programming languages. They may seem similar to <glossterm>Functions</glossterm> but are different in that they must be invoked via the <command>CALL</command> command rather than the <command>SELECT</command> or <command>PERFORM</command> commands, and they are allowed to make transactional statements such as <command>COMMIT</command> and <command>ROLLBACK</command>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createprocedure">SQL Commands: CREATE PROCEDURE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-record">
+    <glossterm>Record</glossterm>
+    <glossdef>
+     <para>
+      A data structure that consists of one or more <glossterm>Attributes</glossterm> in a defined order.
+     </para>
+     <para>
+      A single <glossterm>Row</glossterm> of a <glossterm>Table</glossterm> or other Relation.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-referential-integrity">
+    <glossterm>Referential Integrity</glossterm>
+    <glossdef>
+     <para>
+      The means of restricting data in one <glossterm>Relation</glossterm> such that it must have matching data in another <glossterm>Relation</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-relation">
+    <glossterm>Relation</glossterm>
+    <glossdef>
+     <para>
+      The generic term for all objects in a <glossterm>Database</glossterm> that have a name and a list of <glossterm>Attributes</glossterm> defined in a specific order. <glossterm>Tables</glossterm>, <glossterm>Views</glossterm>, <glossterm>Foreign Tables</glossterm>, <glossterm>Materialized Views</glossterm>, and <glossterm>Indexes</glossterm> are all <glossterm>Relations</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-replica">
+    <glossterm>Replica</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Database</glossterm> that is paired with a Master <glossterm>Database</glossterm> and is maintaining a copy of some or all of the Master <glossterm>Database</glossterm>'s data. The primary reasons for doing this are to allow for greater access to that data, and to maintain availability of the data in the even that the <glossterm>Master</glossterm> becomes unavailable.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-replication">
+    <glossterm>Replication</glossterm>
+    <glossdef>
+     <para>
+       The act of reproducing data on one <glossterm>Server</glossterm> into another called a <glossterm>Replica</glossterm>. This can take the form of Physical <glossterm>Replication</glossterm>, where all file changes from one <glossterm>Server</glossterm> are copied verbatim, or Logical <glossterm>Replication</glossterm> where a defined subset of data changes are conveyed.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-result-set">
+    <glossterm>Result Set</glossterm>
+    <glossdef>
+     <para>
+      A data structure tranmitted from a <glossterm>Server</glossterm> to client program upon the completion of a <acronym>SQL</acronym> command, usually a <command>SELECT</command> but it can be an <command>INSERT</command>, <command>UPDATE</command>, or <command>DELETE</command> command if the <literal>RETURNING</literal> clause is specified. The data structure consists of zero or more <glossterm>Rows</glossterm> with the same ordered set of <glossterm>Attributes</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-revoke">
+    <glossterm>Revoke</glossterm>
+    <glossdef>
+     <para>
+      A command to reduce access to a named set of <glossterm>Database</glossterm> objects for a named list of <glossterm>Users</glossterm> and <glossterm>Roles</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-revoke">SQL Commands: REVOKE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-role">
+    <glossterm>Role</glossterm>
+    <glossdef>
+     <para>
+      A collection of access privileges to the <glossterm>Database</glossterm>. <glossterm>Roles</glossterm> are themselves a privilege that can be granted to other roles. This is often done for convenience or to ensure completeness when multiple Users need the same privileges.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createrole">SQL Commands: CREATE ROLE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-rollback">
+    <glossterm>Rollback</glossterm>
+    <glossdef>
+     <para>
+      A command to undo all of the operations performed since the beginning of a <glossterm>Transaction</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-rollback">SQL Commands: ROLLBACK</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-row">
+    <glossterm>Row</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Tuple</glossterm> or <glossterm>Record</glossterm> found within a <glossterm>Relation</glossterm> or a <glossterm>Result Set</glossterm>. This term is often used interchangably with <glossterm>Record</glossterm> and <glossterm>Tuple</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-savepoint">
+    <glossterm>Savepoint</glossterm>
+    <glossdef>
+     <para>
+      A special mark (such as a timestamp) inside a <glossterm>Transaction</glossterm>. Data modifications after this point in time may be rolled back to the time of the savepoint.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-savepoint">SQL Commands: SAVEPOINT</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-schema">
+    <glossterm>Schema</glossterm>
+    <glossdef>
+     <para>
+      A means of organizing a collection of objects residing in the same <glossterm>Database</glossterm> to facilitate clarity or security. <glossterm>Schema</glossterm>s are most often used in the same way that a namespace is used in programming languages. All objects belong to exactly one <glossterm>Schema</glossterm>, most commonly "public", the default <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+      More generically, the term <glossterm>Schema</glossterm> is used to mean all data descriptions (<glossterm>Table</glossterm> definitions, <glossterm>Constraint</glossterm>s, comments) for a given <glossterm>Database</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-segment">
+    <glossterm>Segment</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>File Segment</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-select">
+    <glossterm>Select</glossterm>
+    <glossdef>
+     <para>
+      The command used to query a <glossterm>Database</glossterm>. Normally, <command>SELECT</command>s are not expected to modify the <glossterm>Database</glossterm> in any way, but it is possible that <glossterm>Functions</glossterm> invoked within the query could have side-effects that do modify data.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-serializable">
+    <glossterm>Serializable</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>Database</glossterm> <glossterm>Session</glossterm>s in a transaction defined as <literal>SERIALIZABLE</literal> are unable to see changes made to the <glossterm>Database</glossterm> by other sessions. In effect, the entire <glossterm>Database</glossterm> appears to be frozen in time for the duration of the <glossterm>Transaction</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-server">
+    <glossterm>Server</glossterm>
+    <glossdef>
+     <para>
+      The term <glossterm>Server</glossterm> denotes real hardware, a container, or a Virtual Machine.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-session">
+    <glossterm>Session</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Connection</glossterm> to the <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      A description of the commands that were issued in the life cycle of a particular <glossterm>Connection</glossterm> to the <glossterm>Database</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-sequence">
+    <glossterm>Sequence</glossterm>
+    <glossdef>
+     <para>
+       An <glossterm>Database</glossterm> object which represents the mathematical concept of a generic numerical sequence. It can be thought of as a <glossterm>Table</glossterm> with exactly one <glossterm>Row</glossterm> and one <glossterm>Column</glossterm>. The value stores is know as the current value. A <glossterm>Sequence</glossterm> has a defined direction (almost always increasing) and an interval step (usually 1).  Whenever the <literal>NEXTVAL</literal> pseudo-column of a <glossterm>Sequence</glossterm> is accessed, the curent value is moved in the defined direction by the defined interval step, and that value is returned to the invoking query, and the current value of the sequence is updated to reflect the new value. The value can be updated multiple times in a single query, the net effect being that each row selected will have a different value. Values taken from a <glossterm>Sequence</glossterm> are never reverted even in the case of a <glossterm>Rollback</glossterm>, which means that the <glossterm>Sequence</glossterm> will never emit the same number twice, and thus is the normal way of generating values to be put in a <glossterm>Primary Key</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createsequence">SQL Commands: CREATE SEQUENCE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-shared-memory">
+    <glossterm>Shared Memory</glossterm>
+    <glossdef>
+     <para>
+      <acronym>RAM</acronym> which is used by the processes common to an <glossterm>Instance</glossterm>. It mirrors parts of <glossterm>Database</glossterm> files, provides an area for <glossterm>WAL Records</glossterm>, and stores additional common information. Note that <glossterm>Shared Memory</glossterm> belongs to the complete <glossterm>Instance</glossterm>, not to a single <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      <glossterm>Shared Memory</glossterm> is organized into pages. If a page is modified, it is called a dirty page until it is written back to the file system.
+     </para>
+     <para>
+      For more information, see <link linkend="runtime-config-resource-memory">Server Configuration: Resource Consumption</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-sql-object">
+    <glossterm>SQL Object</glossterm>
+     <glossdef>
+      <para>
+       A <glossterm>Table</glossterm>, <glossterm>View</glossterm>, <glossterm>Materialized View</glossterm>, <glossterm>Index</glossterm>, <glossterm>Constraint</glossterm>, <glossterm>Sequence</glossterm>, <glossterm>Function</glossterm>, <glossterm>Procedure</glossterm>, <glossterm>Trigger</glossterm>, data type, or operator. Every <glossterm>SQL Object</glossterm> belongs to exactly one <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+       For more information, see <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-stats-collector">
+    <glossterm>Stats Collector</glossterm>
+    <glossdef>
+     <para>
+      This process collects statistical information about the <glossterm>Cluster</glossterm>'s activities.
+     </para>
+     <para>
+       For more information, see <link linkend="monitoring-stats">Monitoring Database Activity: The Statistics Collector</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-system-catalog">
+    <glossterm>System Catalog</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Table</glossterm>s and <glossterm>View</glossterm>s which describe the structure of all <acronym>SQL</acronym> objects of the <glossterm>Database</glossterm> and the <glossterm>Global SQL Objects</glossterm> of the <glossterm>Cluster</glossterm>. The <glossterm>System Catalog</glossterm> resides in the schema <literal>pg_catalog</literal>. Main parts are mirrored as <glossterm>Views</glossterm> in the <glossterm>Schema</glossterm> <literal>information_schema</literal>.
+     </para>
+     <para>
+       For more information, see <link linkend="ddl-schemas">Data Definition: Schemas</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-table">
+    <glossterm>Table</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Tuples</glossterm> (also known as <glossterm>Rows</glossterm> or <glossterm>Records</glossterm>) having a common data structure (the same number of <glossterm>Attributes</glossterm>s, in the same order, having the same name and type). A <glossterm>Table</glossterm> is the most common form of <glossterm>Relation</glossterm> in <productname>PostgreSQL</productname>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-temporary-tables">
+    <glossterm>Temporary Tables</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>Table</glossterm>s that exist either for the lifetime of a <glossterm>Session</glossterm> or a <glossterm>Transaction</glossterm>, as defined at creation time. The data in them is not visible to other <glossterm>Sessions</glossterm>, and is not <glossterm>Logged</glossterm>. <glossterm>Temporary Tables</glossterm> are most often used to store intermediate data for a multi-step data transformation.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-transaction">
+    <glossterm>Transaction</glossterm>
+    <glossdef>
+     <para>
+      A combination of one or more commands that must act as a single <glossterm>Atomic</glossterm> command: they all succeed or fail together, and their effects are not visible to other sessions until the <glossterm>Transaction</glossterm> is complete.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-trigger">
+    <glossterm>Trigger</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Function</glossterm> which can be defined to execute whenever a certain operation (<command>INSERT</command>, <command>UPDATE</command>, or <command>DELTE</command>) is applied to that <glossterm>Relation</glossterm>. A <glossterm>Trigger</glossterm> executes within the same <glossterm>Transaction</glossterm> as the statement which invoked it, and if the <glossterm>Function</glossterm> fails then the invoking statement also fails.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createtrigger">SQL Commands: CREATE TRIGGER</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-tuple">
+    <glossterm>Tuple</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Attributes</glossterm> in a fixed order. That order may be defined by the <glossterm>Table</glossterm> where the <glossterm>Tuple</glossterm> is found, in which case the <glossterm>Tuple</glossterm> is often called a <glossterm>Row</glossterm> or <glossterm>Record</glossterm>. It may also be defined by the structure of a <glossterm>Result Set</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-unique">
+    <glossterm>Unique</glossterm>
+    <glossdef>
+     <para>
+      The condition of having no matching values in the same <glossterm>Relation</glossterm>. Most often used in the concept of <glossterm>Unique Indexes</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-unlogged">
+    <glossterm>Unlogged</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that is unlogged will not have changes reflected in the <glossterm>WAL Log</glossterm>,
+which would enable those changes to be duplicated on a <glossterm>Replica</glossterm>, and also enables the change to survive a <glossterm>Database</glossterm> crash.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-update">
+    <glossterm>Update</glossterm>
+    <glossdef>
+     <para>
+      A command used to modify <glossterm>Rows</glossterm> that already exist in a specified <glossterm>Table</glossterm>. It
+cannot create <glossterm>Rows</glossterm> nor can it remove <glossterm>Rows</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-update">SQL Commands: UPDATE</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-user">
+    <glossterm>User</glossterm>
+    <glossdef>
+     <para>
+      A specific case of a <glossterm>Role</glossterm> that is entitled to access (log into) the <glossterm>Database</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-user-mapping">
+    <glossterm>User Mapping</glossterm>
+    <glossdef>
+     <para>
+      The translation of user credentials in the local <glossterm>Database</glossterm> to credentials in a remote data system defined by a <glossterm>Foreign Data Wrapper</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createusermapping">SQL Commands: CREATE USER MAPPING</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-view">
+    <glossterm>View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that is defined by a <command>SELECT</command> statement, but has no storage of its own. Any time a query references a <glossterm>View</glossterm>, the definition of the <glossterm>View</glossterm> is substituted into the query as if the user had typed that subquery instead of the name of the <glossterm>View</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createview">SQL Commands: CREATE VIEW</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-file">
+    <glossterm>WAL File</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>WAL Records</glossterm> are continously written to the end of the current <glossterm>WAL File</glossterm>.  <glossterm>WAL Files</glossterm> as well as <glossterm>WAL Records</glossterm> belong to the complete <glossterm>Cluster</glossterm>, not to a single <glossterm>Database</glossterm>. After a <glossterm>WAL File</glossterm> is full, a new <glossterm>WAL File</glossterm> is created or, under certain conditions, one of the previous <glossterm>WAL Files</glossterm> is renamed and reused.
+     </para>
+     <para>
+      The sequence of <glossterm>WAL Records</glossterm> in combination with the sequence of <glossterm>WAL Files</glossterm> represents the sequence of changes that have taken place in the <glossterm>Cluster</glossterm>.
+     </para>
+      <para>
+       For more information, see <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+    <glossentry id="glossary-wal-log">
+    <glossterm>WAL Log</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-record">
+    <glossterm>WAL Record</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>WAL Record</glossterm> contains either new or changed <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> data or other binary information about a <command>COMMIT</command>, <command>ROLLBACK</command>, <command>SAVEPOINT</command>, or <glossterm>Checkpointer</glossterm> operation.
+     </para>
+      <para>
+       For more information, see <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-segment">
+    <glossterm>WAL Segment</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-segment-file">
+    <glossterm>WAL Segment File</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-writer">
+   <glossterm>WAL Writer</glossterm>
+   <glossdef>
+    <para>
+     This process writes <glossterm>WAL Records</glossterm> from <glossterm>Shared Memory</glossterm> to <glossterm>WAL Files</glossterm>.
+    </para>
+      <para>
+       For more information, see <link linkend="runtime-config-wal">Server Configuration: Write Ahead Log</link>.
+     </para>
+   </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-window-function">
+    <glossterm>Window Function</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Function</glossterm> similar to an <glossterm>Aggregate</glossterm> in that can derive its value
+from a set of <glossterm>Rows</glossterm> in a <glossterm>Result Set</glossterm>, but still retaining the original source
+data.
+     </para>
+     <para>
+      For more information, see <link linkend="tutorial-window">Window Functions</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+  </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index e59cba7997..2183e33bea 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
   &docguide;
   &limits;
   &acronyms;
+  &glossary;
 
  </part>
 
-- 
2.20.1

diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index 851e9debe6..52169b86a2 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1,7 +1,7 @@
 <appendix id="glossary">
  <title>Glossary</title>
  <para>
-  This is a list of terms and their in the context of <productname>PostgreSQL</productname> and <glossterm>Database</glossterm>s in general.
+  This is a list of terms and their meaning in the context of <productname>PostgreSQL</productname> and <glossterm>Database</glossterm>s in general.
  </para>
   <glosslist>
    <glossentry id="glossary-aggregate">
@@ -44,7 +44,7 @@
     <glossterm>Atomic</glossterm>
     <glossdef>
      <para>
-      In reference to the value of an <glossterm>Attribute</glossterm> or <glossterm>Datum</glossterm>: cannot be broken up into smaller components.
+      In reference to the value of an <glossterm>Attribute</glossterm> or <glossterm>Datum</glossterm>: cannot be broken down into smaller components.
      </para>
      <para>
       In reference to an operation: An event that cannot be completed in part: it must either entirely succeed or entirely fail. A series of <acronym>SQL</acronym> statements can be combined into a <glossterm>Transaction</glossterm>, and that <glossterm>transaction</glossterm> is said to be <glossterm>Atomic</glossterm>.
@@ -56,7 +56,7 @@
     <glossterm>Attribute</glossterm>
     <glossdef>
      <para>
-      A typed data element found within a <glossterm>Tuple</glossterm> or <glossterm>Relation</glossterm> or <glossterm>Table</glossterm>.
+      An element with a certain name and data type found within a <glossterm>Tuple</glossterm> or <glossterm>Table</glossterm>.
      </para>
     </glossdef>
    </glossentry>
@@ -164,12 +164,30 @@ any <glossterm>Attribute</glossterm> in the <glossterm>Relation</glossterm>, but
     </glossdef>
    </glossentry>
 
+   <glossentry id="glossary-checkpoint">
+    <glossterm>Checkpoint</glossterm>
+    <glossdef>
+     <para>
+      A <link linkend="sql-checkpoint">
+      Checkpoint</link>
+      is a point in time when all older dirty
+      pages of the <glossterm>Shared Memory</glossterm>,
+      all older <glossterm>WAL records</glossterm>, and a
+      special <glossterm>Checkpoint record</glossterm>
+      have been written and flushed to disk.
+     </para>
+    </glossdef>
+   </glossentry>
+
    <glossentry id="glossary-cluster">
     <glossterm>Cluster</glossterm>
     <glossdef>
      <para>
       A group of <glossterm>Database</glossterm>s plus their <glossterm>Global SQL Objects</glossterm>. The <glossterm>Cluster</glossterm> is managed by exactly one <glossterm>Instance</glossterm>. A newly created <glossterm>Cluster</glossterm> will have three <glossterm>Databases</glossterm> created automatically. They are <literal>template0</literal>, <literal>template1</literal>, and <literal>postgres</literal>. It is expected that an application will create one or more additional <glossterm>Databases</glossterm> aside from these three.
      </para>
+     <para>
+      Don't confuse the <productname>PostgreSQL</productname> specific term <glossterm>Cluster</glossterm> with the SQL command <literal>Cluster</literal>.
+     </para>
     </glossdef>
    </glossentry>
 
@@ -198,7 +216,7 @@ any <glossterm>Attribute</glossterm> in the <glossterm>Relation</glossterm>, but
     <glossterm>Concurrency</glossterm>
     <glossdef>
      <para>
-      The concept that multiple independent operations can be happening within the <glossterm>Database</glossterm> at the same time.
+      The concept that multiple independent operations happen within the <glossterm>Database</glossterm> at the same time.
      </para>
     </glossdef>
    </glossentry>
@@ -216,7 +234,7 @@ any <glossterm>Attribute</glossterm> in the <glossterm>Relation</glossterm>, but
     <glossterm>Constraint</glossterm>
     <glossdef>
      <para>
-      A method of restricting the values of data allowed within a <glossterm>Table</glossterm>.
+      A concept of restricting the values of data allowed within a <glossterm>Table</glossterm>.
      </para>
      <para>
       For more information, see <link linkend="ddl-constraints">Constraints</link>.
@@ -238,7 +256,7 @@ any <glossterm>Attribute</glossterm> in the <glossterm>Relation</glossterm>, but
     <glossdef>
      <para>
       The base directory on the filesystem of a <glossterm>Server</glossterm> that contains all data
-files and subdirectories associated with a <glossterm>Cluster</glossterm>. The name for this directory in configuration files is <productname>PGDATA</productname>.
+      files and subdirectories associated with a <glossterm>Cluster</glossterm> with the exception of tablespaces. The environment variable <literal>PGDATA</literal> often - but not always - referes to the <glossterm>Data Directory</glossterm>.
      </para>
      <para>
       For more information, see <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
@@ -250,7 +268,7 @@ files and subdirectories associated with a <glossterm>Cluster</glossterm>. The n
     <glossterm>Database</glossterm>
     <glossdef>
      <para>
-      A named collection of <glossterm>SQL Objects</glossterm>.    
+      A named collection of <glossterm>SQL Objects</glossterm>.
      </para>
      <para>
       For more information, see <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
@@ -292,14 +310,13 @@ files and subdirectories associated with a <glossterm>Cluster</glossterm>. The n
     <glossterm>File Segment</glossterm>
     <glossdef>
      <para>
-       If a <glossterm>Database</glossterm> object grows in size past a designated limit, it may be
-split into multiple physical files. These files are called <glossterm>File Segments</glossterm>.
+       If a heap or index file grows in size over 1 GB, it will be split into multiple physical files. These files are called <glossterm>File Segments</glossterm>.
      </para>
      <para>
-      (Don't confuse this term with the similar term <glossterm>WAL Segment</glossterm>).
+      For more information, see <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
      </para>
      <para>
-      For more information, see <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+      (Don't confuse this term with the similar term <glossterm>WAL Segment</glossterm>).
      </para>
     </glossdef>
    </glossentry>
@@ -353,7 +370,7 @@ split into multiple physical files. These files are called <glossterm>File Segme
     <glossterm>Function</glossterm>
     <glossdef>
      <para>
-      Any pre-defined tranformation of data. Many <glossterm>Functions</glossterm> are already defined within <productname>PostgreSQL</productname> itself, but can also be user-defined.
+      Any pre-defined transformation of data. Many <glossterm>Functions</glossterm> are already defined within <productname>PostgreSQL</productname> itself, but can also be user-defined.
      </para>
      <para>
       For more information, see <link linkend="sql-createfunction">SQL Commands: CREATE FUNCTION</link>.
@@ -365,7 +382,7 @@ split into multiple physical files. These files are called <glossterm>File Segme
     <glossterm>Global SQL Object</glossterm>
     <glossdef>
      <para>
-      Not all objects belong to a certain <glossterm>Schema</glossterm>, or to their <glossterm>Database</glossterm>, or even to the complete <glossterm>Cluster</glossterm>. These are referred to as <glossterm>Global SQL Objects</glossterm>. Collations and Extensions such as <glossterm>Foreign Data Wrappers</glossterm> reside at the <glossterm>Database</glossterm> level; <glossterm>Database</glossterm> names, <glossterm>Roles</glossterm>, <glossterm>Tablespaces</glossterm>, <glossterm>Replication</glossterm> origins, and subscriptions for logical <glossterm>Replication</glossterm> at the <glossterm>Cluster</glossterm> level.
+      Not all <glossterm>SQL Objects</glossterm> belong to a certain <glossterm>Schema</glossterm>. Some belong to the complete <glossterm>Database</glossterm>, or even to the complete <glossterm>Cluster</glossterm>. These are referred to as <glossterm>Global SQL Objects</glossterm>. Collations and Extensions such as <glossterm>Foreign Data Wrappers</glossterm> reside at the <glossterm>Database</glossterm> level; <glossterm>Database</glossterm> names, <glossterm>Roles</glossterm>, <glossterm>Tablespaces</glossterm>, <glossterm>Replication</glossterm> origins, and subscriptions for logical <glossterm>Replication</glossterm> at the <glossterm>Cluster</glossterm> level.
      </para>
     </glossdef>
    </glossentry>
@@ -391,7 +408,7 @@ split into multiple physical files. These files are called <glossterm>File Segme
     </glossdef>
    </glossentry>
 
-   <glossentry id="host">
+   <glossentry id="glossary-host">
     <glossterm>Host</glossterm>
     <glossdef>
      <para>
@@ -404,7 +421,7 @@ split into multiple physical files. These files are called <glossterm>File Segme
     <glossterm>Index</glossterm>
     <glossdef>
      <para>
-      A <glossterm>Relation</glossterm> that contains data derived from a <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> such as a <glossterm>Materialized View</glossterm>) that stores the data in a way that makes specific values easier to retrieve.
+      A <glossterm>Relation</glossterm> that contains data derived from a <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> such as a <glossterm>Materialized View</glossterm>). It's internal structure supports very fast retrieval of and access to the original data.
      </para>
      <para>
       For more information, see <link linkend="sql-createindex">SQL Commands: CREATE INDEX</link>.
@@ -466,7 +483,33 @@ split into multiple physical files. These files are called <glossterm>File Segme
     </glossdef>
    </glossentry>
 
-   <glossentry id="log-record">
+   <glossentry id="glossary-log-file">
+    <glossterm>Log File</glossterm>
+    <glossdef>
+     <para>
+      <link linkend="logfile-maintenance">LOG files</link>
+      contain readable text lines about serious
+      and non-serious events, e.g.: use of
+      wrong password, long-running queries, ... .
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-writer">
+    <glossterm>Log Writer</glossterm>
+    <glossdef>
+     <para>
+      If activated and parameterized, the
+      <link linkend="runtime-config-logging">Log Writer</link>
+      process writes information about database events into the
+      current <glossterm>Log file</glossterm>. When reaching
+      certain time- or volume-dependent criterias, he creates
+      a new <glossterm>Log file</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-record">
     <glossterm>Log Record</glossterm>
      <glossdef>
       <para>
@@ -528,10 +571,10 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Partition</glossterm>
     <glossdef>
      <para>
-      A <glossterm>Table</glossterm> that can be queried independently by its own name, but can also be queried via another <glossterm>Table</glossterm>, a partitioend <glossterm>Table</glossterm>, which is a collection of sub-<glossterm>Table</glossterm>s, each capable of holding one defined subset of information that does not overlap with any other <glossterm>Table</glossterm> in the set of <glossterm>Table</glossterm>s.
+      a) A <glossterm>Table</glossterm> that can be queried independently by its own name, but can also be queried via another <glossterm>Table</glossterm>, a partitionend <glossterm>Table</glossterm>, which is a collection of sub-<glossterm>Table</glossterm>s, each capable of holding one defined subset of information that does not overlap with any other <glossterm>Table</glossterm> in the set of <glossterm>Table</glossterm>s.
      </para>
      <para>
-      A defined boundary used in an <glossterm>Analytic</glossterm> <glossterm>Function</glossterm> to identify which neighboring <glossterm>Rows</glossterm> can be considered by the <glossterm>Function</glossterm> for this particular <glossterm>Row</glossterm>.
+      b) A defined boundary used in an <glossterm>Analytic</glossterm> <glossterm>Function</glossterm> to identify which neighboring <glossterm>Rows</glossterm> can be considered by the <glossterm>Function</glossterm> for this particular <glossterm>Row</glossterm>.
      </para>
     </glossdef>
    </glossentry>
@@ -573,7 +616,7 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Record</glossterm>
     <glossdef>
      <para>
-      A data structure that consists of one or more <glossterm>Attributes</glossterm> in a defined order.
+      See <link linkend="sql-revoke">Tupple</link>.
      </para>
      <para>
       A single <glossterm>Row</glossterm> of a <glossterm>Table</glossterm> or other Relation.
@@ -603,7 +646,7 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Replica</glossterm>
     <glossdef>
      <para>
-      A <glossterm>Database</glossterm> that is paired with a Master <glossterm>Database</glossterm> and is maintaining a copy of some or all of the Master <glossterm>Database</glossterm>'s data. The primary reasons for doing this are to allow for greater access to that data, and to maintain availability of the data in the even that the <glossterm>Master</glossterm> becomes unavailable.
+      A <glossterm>Database</glossterm> that is paired with a Master <glossterm>Database</glossterm> and is maintaining a copy of some or all of the Master <glossterm>Database</glossterm>'s data. The primary reasons for doing this are to allow for greater access to that data, and to maintain availability of the data in the event that the <glossterm>Master</glossterm> becomes unavailable.
      </para>
     </glossdef>
    </glossentry>
@@ -621,7 +664,7 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Result Set</glossterm>
     <glossdef>
      <para>
-      A data structure tranmitted from a <glossterm>Server</glossterm> to client program upon the completion of a <acronym>SQL</acronym> command, usually a <command>SELECT</command> but it can be an <command>INSERT</command>, <command>UPDATE</command>, or <command>DELETE</command> command if the <literal>RETURNING</literal> clause is specified. The data structure consists of zero or more <glossterm>Rows</glossterm> with the same ordered set of <glossterm>Attributes</glossterm>.
+      A data structure transmitted from a <glossterm>Server</glossterm> to client program upon the completion of a <acronym>SQL</acronym> command, usually a <command>SELECT</command> but it can be an <command>INSERT</command>, <command>UPDATE</command>, or <command>DELETE</command> command if the <literal>RETURNING</literal> clause is specified. The data structure consists of zero or more <glossterm>Rows</glossterm> with the same ordered set of <glossterm>Attributes</glossterm>.
      </para>
     </glossdef>
    </glossentry>
@@ -666,7 +709,7 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Row</glossterm>
     <glossdef>
      <para>
-      A <glossterm>Tuple</glossterm> or <glossterm>Record</glossterm> found within a <glossterm>Relation</glossterm> or a <glossterm>Result Set</glossterm>. This term is often used interchangably with <glossterm>Record</glossterm> and <glossterm>Tuple</glossterm>.
+      See <link linkend="sql-revoke">Tupple</link>.
      </para>
     </glossdef>
    </glossentry>
@@ -687,7 +730,22 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Schema</glossterm>
     <glossdef>
      <para>
-      A means of organizing a collection of objects residing in the same <glossterm>Database</glossterm> to facilitate clarity or security. <glossterm>Schema</glossterm>s are most often used in the same way that a namespace is used in programming languages. All objects belong to exactly one <glossterm>Schema</glossterm>, most commonly "public", the default <glossterm>Schema</glossterm>.
+      A <link linkend="ddl-schemas">schema</link> is a
+      namespace for <glossterm>SQL objects</glossterm>, which
+      all reside in the same <glossterm>database</glossterm>.
+      Each <glossterm>SQL object</glossterm> must reside in
+      exactly one <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+      The names of <glossterm>SQL objects</glossterm> in the
+      schema are unique - even across different types of objects.
+      Same object names can only be used in different schemas.
+     </para>
+     <para>
+     Many <glossterm>SQL objects</glossterm> reside in the default
+     <glossterm>Schema</glossterm> <literal>public</literal>, but it
+     is expected that more schemas are created to hold application
+     specific <glossterm>SQL objects</glossterm>.
      </para>
      <para>
       More generically, the term <glossterm>Schema</glossterm> is used to mean all data descriptions (<glossterm>Table</glossterm> definitions, <glossterm>Constraint</glossterm>s, comments) for a given <glossterm>Database</glossterm>.
@@ -717,7 +775,7 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Serializable</glossterm>
     <glossdef>
      <para>
-      <glossterm>Database</glossterm> <glossterm>Session</glossterm>s in a transaction defined as <literal>SERIALIZABLE</literal> are unable to see changes made to the <glossterm>Database</glossterm> by other sessions. In effect, the entire <glossterm>Database</glossterm> appears to be frozen in time for the duration of the <glossterm>Transaction</glossterm>.
+      Transactions defined as <literal>SERIALIZABLE</literal> are unable to see changes made within other transactions. In effect, for the initializing session the entire <glossterm>Database</glossterm> appears to be frozen duration such a <glossterm>Transaction</glossterm>. (??? Isn't it the other way round: changes done by serializable transactions are not seen by other transactions ???)
      </para>
     </glossdef>
    </glossentry>
@@ -747,7 +805,7 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Sequence</glossterm>
     <glossdef>
      <para>
-       An <glossterm>Database</glossterm> object which represents the mathematical concept of a generic numerical sequence. It can be thought of as a <glossterm>Table</glossterm> with exactly one <glossterm>Row</glossterm> and one <glossterm>Column</glossterm>. The value stores is know as the current value. A <glossterm>Sequence</glossterm> has a defined direction (almost always increasing) and an interval step (usually 1).  Whenever the <literal>NEXTVAL</literal> pseudo-column of a <glossterm>Sequence</glossterm> is accessed, the curent value is moved in the defined direction by the defined interval step, and that value is returned to the invoking query, and the current value of the sequence is updated to reflect the new value. The value can be updated multiple times in a single query, the net effect being that each row selected will have a different value. Values taken from a <glossterm>Sequence</glossterm> are never reverted even in the case of a <glossterm>Rollback</glossterm>, which means that the <glossterm>Sequence</glossterm> will never emit the same number twice, and thus is the normal way of generating values to be put in a <glossterm>Primary Key</glossterm>.
+       An <glossterm>Database</glossterm> object which represents the mathematical concept of a numerical integral sequence. It can be thought of as a <glossterm>Table</glossterm> with exactly one <glossterm>Row</glossterm> and one <glossterm>Column</glossterm>. The value stored is known as the current value. A <glossterm>Sequence</glossterm> has a defined direction (almost always increasing) and an interval step (usually 1).  Whenever the <literal>NEXTVAL</literal> pseudo-column of a <glossterm>Sequence</glossterm> is accessed, the curent value is moved in the defined direction by the defined interval step, and that value is returned to the invoking query, and the current value of the sequence is updated to reflect the new value. The value can be updated multiple times in a single query, the net effect being that each row selected will have a different value. Values taken from a <glossterm>Sequence</glossterm> are never reverted even in the case of a <glossterm>Rollback</glossterm>, which means that the <glossterm>Sequence</glossterm> will never emit the same number twice, and thus is the normal way of generating values to be put in a <glossterm>Primary Key</glossterm>.
      </para>
      <para>
       For more information, see <link linkend="sql-createsequence">SQL Commands: CREATE SEQUENCE</link>.
@@ -810,7 +868,7 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Table</glossterm>
     <glossdef>
      <para>
-      A collection of <glossterm>Tuples</glossterm> (also known as <glossterm>Rows</glossterm> or <glossterm>Records</glossterm>) having a common data structure (the same number of <glossterm>Attributes</glossterm>s, in the same order, having the same name and type). A <glossterm>Table</glossterm> is the most common form of <glossterm>Relation</glossterm> in <productname>PostgreSQL</productname>.
+      A collection of <glossterm>Tuples</glossterm> (also known as <glossterm>Rows</glossterm> or <glossterm>Records</glossterm>) having a common data structure (the same number of <glossterm>Attributes</glossterm>s, in the same order, having the same name and type per position). A <glossterm>Table</glossterm> is the most common form of <glossterm>Relation</glossterm> in <productname>PostgreSQL</productname>.
      </para>
      <para>
       For more information, see <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>.
@@ -834,7 +892,7 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Transaction</glossterm>
     <glossdef>
      <para>
-      A combination of one or more commands that must act as a single <glossterm>Atomic</glossterm> command: they all succeed or fail together, and their effects are not visible to other sessions until the <glossterm>Transaction</glossterm> is complete.
+      A combination of one or more commands that must act as a single <glossterm>Atomic</glossterm> command: they all succeed or fail together, and their effects are not visible to other sessions until the <glossterm>Transaction</glossterm> is complete. (??? non repeatable read, phantom read, serialization ananomaly are possible ???)
      </para>
     </glossdef>
    </glossentry>
@@ -873,8 +931,8 @@ data in the same way that a <glossterm>Table</glossterm> does. it cannot be modi
     <glossterm>Unlogged</glossterm>
     <glossdef>
      <para>
-      A <glossterm>Relation</glossterm> that is unlogged will not have changes reflected in the <glossterm>WAL Log</glossterm>,
-which would enable those changes to be duplicated on a <glossterm>Replica</glossterm>, and also enables the change to survive a <glossterm>Database</glossterm> crash.
+      Changes to an unlogged <glossterm>Relation</glossterm> are not reflected in the <glossterm>WAL Log</glossterm>.
+      This disables replication and crash recovery for such <glossterm>Relations</glossterm>.
      </para>
     </glossdef>
    </glossentry>
@@ -953,7 +1011,7 @@ cannot create <glossterm>Rows</glossterm> nor can it remove <glossterm>Rows</glo
     <glossterm>WAL Record</glossterm>
     <glossdef>
      <para>
-      A <glossterm>WAL Record</glossterm> contains either new or changed <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> data or other binary information about a <command>COMMIT</command>, <command>ROLLBACK</command>, <command>SAVEPOINT</command>, or <glossterm>Checkpointer</glossterm> operation.
+      A <glossterm>WAL Record</glossterm> contains either new or changed <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> data or information about a <command>COMMIT</command>, <command>ROLLBACK</command>, <command>SAVEPOINT</command>, or <glossterm>Checkpointer</glossterm> operation. WAL records use a non-printabe binary format.
      </para>
       <para>
        For more information, see <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.

From dbce6922194eb4ad8de57e81e182b9a6eebf859e Mon Sep 17 00:00:00 2001
From: coreyhuinker <corey.huinker@gmail.com>
Date: Tue, 10 Mar 2020 11:26:29 -0400
Subject: [PATCH] add glossary page with revisions

---
 doc/src/sgml/filelist.sgml |    1 +
 doc/src/sgml/glossary.sgml | 1072 ++++++++++++++++++++++++++++++++++++
 doc/src/sgml/postgres.sgml |    1 +
 3 files changed, 1074 insertions(+)
 create mode 100644 doc/src/sgml/glossary.sgml

diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 3da2365ea9..504c8a6326 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY glossary   SYSTEM "glossary.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..d28bfb6fcf
--- /dev/null
+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,1072 @@
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+  This is a list of terms and their meaning in the context of <productname>PostgreSQL</productname> and <glossterm>Database</glossterm>s in general.
+ </para>
+  <glosslist>
+   <glossentry id="glossary-aggregate">
+    <glossterm>Aggregate</glossterm>
+    <glossdef>
+     <para>
+      To combine a collection of data values into a single value, whose value may not be of the same type as the original values. <glossterm>Aggregate</glossterm> <glossterm>Functions</glossterm> combine multiple <glossterm>Rows</glossterm> that share a common set of values into one <glossterm>Row</glossterm>, which means that the only data visible in the values in common, and the aggregates of the non-common data.
+     </para>
+     <para>
+      For more information, see <link linkend="functions-aggregate">Aggregate Functions</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-analytic">
+    <glossterm>Analytic</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Function</glossterm> whose computed value can reference values found in nearby <glossterm>Rows</glossterm> of the same <glossterm>Result Set</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="tutorial-window">Window Functions</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-archiver">
+    <glossterm>Archiver</glossterm>
+    <glossdef>
+     <para>
+      A process that backs up <glossterm>WAL Files</glossterm> in order to reclaim space on the file system.
+     </para>
+     <para>
+      For more information, see <link linkend="continuous-archiving">Backup and Restore: Continuous Archiving and Point-in-Time Recovery (PITR)</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-atomic">
+    <glossterm>Atomic</glossterm>
+    <glossdef>
+     <para>
+      In reference to the value of an <glossterm>Attribute</glossterm> or <glossterm>Datum</glossterm>: cannot be broken down into smaller components.
+     </para>
+     <para>
+      In reference to an operation: An event that cannot be completed in part: it must either entirely succeed or entirely fail. A series of <acronym>SQL</acronym> statements can be combined into a <glossterm>Transaction</glossterm>, and that <glossterm>transaction</glossterm> is said to be <glossterm>Atomic</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-attribute">
+    <glossterm>Attribute</glossterm>
+    <glossdef>
+     <para>
+      An element with a certain name and data type found within a <glossterm>Tuple</glossterm> or <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-autovacuum">
+    <glossterm>Autovacuum</glossterm>
+    <glossdef>
+     <para>
+      Processes that remove outdated <acronym>MVCC</acronym> <glossterm>Records</glossterm> of the <glossterm>Heap</glossterm> and <glossterm>Index</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="routine-vacuuming">Routine Database Maintenance Tasks: Routine Vacuuming</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-backend-process">
+    <glossterm>Backend Process</glossterm>
+    <glossdef>
+     <para>
+      Processes of an <glossterm>Instance</glossterm> which act on behalf of client <glossterm>Connections</glossterm> and handle their requests.
+     </para>
+     <para>
+      (Don't confuse this term with the similar terms <glossterm>Background Worker</glossterm> or <glossterm>Background Writer</glossterm>).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-backend-server">
+    <glossterm>Backend Server</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Instance</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-background-worker">
+    <glossterm>Background Worker</glossterm>
+    <glossdef>
+     <para>
+      Individual processes within an <glossterm>Instance</glossterm>, which run system- or user-supplied code. Typical use cases are processes which handle parts of an <acronym>SQL</acronym> query to take advantage of parallel execution on servers with multiple <acronym>CPUs</acronym>.
+    </para>
+    <para>
+     For more information, see <link linkend="bgworker">Background Worker Processes</link>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-background-writer">
+    <glossterm>Background Writer</glossterm>
+    <glossdef>
+     <para>
+      Writes continuously dirty pages from <glossterm>Shared Memory</glossterm> to the file system. It starts periodically, but works only for a short period in order to distribute
+expensive <acronym>I/O</acronym> activity over time instead of generating fewer large <acronym>I/O</acronym> peaks which could block other processes.
+     </para>
+     <para>
+      For more information, see <link linkend="runtime-config-resource">Server Configuration: Resource Consumption</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-cast">
+    <glossterm>Cast</glossterm>
+    <glossdef>
+     <para>
+      A conversion of a <glossterm>Datum</glossterm> from its current data type to another data type.
+     </para>
+    </glossdef>
+   </glossentry>
+
+ <glossentry id="glossary-catalog">
+    <glossterm>Catalog</glossterm>
+    <glossdef>
+     <para>
+      The <acronym>SQL</acronym> standard uses this standalone term to indicate what is called a
+<glossterm>Database</glossterm> in <productname>PostgreSQL</productname>'s terminology.
+     </para>
+     <para>
+      For more information, see <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-check-constraint">
+    <glossterm>Check Constraint</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Constraint</glossterm> defined on a <glossterm>Relation</glossterm> which restricts the values
+allowed in one or more <glossterm>Attributes</glossterm>. The <glossterm>Check Constraint</glossterm> can make reference to
+any <glossterm>Attribute</glossterm> in the <glossterm>Relation</glossterm>, but cannot reference other <glossterm>Rows</glossterm> of the same <glossterm>Relation</glossterm> or other <glossterm>Relations</glossterm>.
+     </para>
+    <para>
+     For more information, see <link linkend="ddl-constraints">Constraints</link>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-checkpointer">
+    <glossterm>Checkpointer</glossterm>
+    <glossdef>
+     <para>
+      A process that writes dirty pages and <glossterm>WAL Records</glossterm> to the file system and creates a special checkpoint record. This process is initiated when predefined conditions are met, such as a specified amount of time has passed, or a certain volume of records have been collected.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-checkpoint">
+    <glossterm>Checkpoint</glossterm>
+    <glossdef>
+     <para>
+      A <link linkend="sql-checkpoint">
+      Checkpoint</link>
+      is a point in time when all older dirty
+      pages of the <glossterm>Shared Memory</glossterm>,
+      all older <glossterm>WAL records</glossterm>, and a
+      special <glossterm>Checkpoint record</glossterm>
+      have been written and flushed to disk.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-cluster">
+    <glossterm>Cluster</glossterm>
+    <glossdef>
+     <para>
+      A group of <glossterm>Database</glossterm>s plus their <glossterm>Global SQL Objects</glossterm>. The <glossterm>Cluster</glossterm> is managed by exactly one <glossterm>Instance</glossterm>. A newly created <glossterm>Cluster</glossterm> will have three <glossterm>Databases</glossterm> created automatically. They are <literal>template0</literal>, <literal>template1</literal>, and <literal>postgres</literal>. It is expected that an application will create one or more additional <glossterm>Databases</glossterm> aside from these three.
+     </para>
+     <para>
+      Don't confuse the <productname>PostgreSQL</productname> specific term <glossterm>Cluster</glossterm> with the SQL command <literal>Cluster</literal>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-column">
+    <glossterm>Column</glossterm>
+    <glossdef>
+     <para>
+      An <glossterm>Attribute</glossterm> found in a <glossterm>Table</glossterm> or <glossterm>View</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-commit">
+    <glossterm>Commit</glossterm>
+    <glossdef>
+     <para>
+      The act of finalizing a <glossterm>Transaction</glossterm> within the <glossterm>Database</glossterm>.
+     </para>
+    <para>
+     For more information, see <link linkend="sql-commit">SQL Commands: COMMIT</link>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-concurrency">
+    <glossterm>Concurrency</glossterm>
+    <glossdef>
+     <para>
+      The concept that multiple independent operations happen within the <glossterm>Database</glossterm> at the same time.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-connection">
+    <glossterm>Connection</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>TCP/IP</acronym> or socket line for inter-process communication. If the two involved processes reside on different servers, <acronym>TCP/IP</acronym> must be used.  Otherwise both techniques are possible.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-constraint">
+    <glossterm>Constraint</glossterm>
+    <glossdef>
+     <para>
+      A concept of restricting the values of data allowed within a <glossterm>Table</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="ddl-constraints">Constraints</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-data-area">
+    <glossterm>Data Area</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Data Directory</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-data-directory">
+    <glossterm>Data Directory</glossterm>
+    <glossdef>
+     <para>
+      The base directory on the filesystem of a <glossterm>Server</glossterm> that contains all data
+      files and subdirectories associated with a <glossterm>Cluster</glossterm> with the exception of tablespaces. The environment variable <literal>PGDATA</literal> often - but not always - referes to the <glossterm>Data Directory</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-database">
+    <glossterm>Database</glossterm>
+    <glossdef>
+     <para>
+      A named collection of <glossterm>SQL Objects</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-database-server">
+    <glossterm>Database Server</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Instance</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-datum">
+    <glossterm>Datum</glossterm>
+    <glossdef>
+     <para>
+      The internal representation of a <acronym>SQL</acronym> data type.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-delete">
+    <glossterm>Delete</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command whose purpose is to remove <glossterm>Rows</glossterm> from a given <glossterm>Table</glossterm> or <glossterm>Relation</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-delete">SQL Commands: DELETE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-file-segment">
+    <glossterm>File Segment</glossterm>
+    <glossdef>
+     <para>
+       If a heap or index file grows in size over 1 GB, it will be split into multiple physical files. These files are called <glossterm>File Segments</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+     </para>
+     <para>
+      (Don't confuse this term with the similar term <glossterm>WAL Segment</glossterm>).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-data-wrapper">
+    <glossterm>Foreign Data Wrapper</glossterm>
+    <glossdef>
+     <para>
+      A means of representing data that is not contained in the local <glossterm>Database</glossterm> as if were in local <glossterm>Table</glossterm>(s). With a Foreign Data Wrapper it is possible to define a <glossterm>Foreign Server</glossterm> and <glossterm>Foreign Tables</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createforeigndatawrapper">SQL Commands: CREATE FOREIGN DATA WRAPPER</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-key">
+    <glossterm>Foreign Key</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Constraint</glossterm> defined on one or more <glossterm>Column</glossterm>s in a <glossterm>Table</glossterm> which requires the value in those <glossterm>Column</glossterm>s to uniquely identify a <glossterm>Row</glossterm> in the specified <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-server">
+    <glossterm>Foreign Server</glossterm>
+    <glossdef>
+     <para>
+      A named collection of <glossterm>Foreign Tables</glossterm> which all use the same <glossterm>Foreign Data Wrapper</glossterm> and have other configuration values in common.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createserver">SQL Commands: CREATE SERVER</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-table">
+    <glossterm>Foreign Table</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> which appears to have <glossterm>Rows</glossterm> and <glossterm>Columns</glossterm> similar to a regular <glossterm>Table</glossterm>, but will forward requests for data through its <glossterm>Foreign Data Wrapper</glossterm>, which will return <glossterm>Result Sets</glossterm> structured according to the definition of the <glossterm>Foreign Table</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createforeigntable">SQL Commands: CREATE FOREIGN TABLE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-function">
+    <glossterm>Function</glossterm>
+    <glossdef>
+     <para>
+      Any pre-defined transformation of data. Many <glossterm>Functions</glossterm> are already defined within <productname>PostgreSQL</productname> itself, but can also be user-defined.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createfunction">SQL Commands: CREATE FUNCTION</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-global-sql-object">
+    <glossterm>Global SQL Object</glossterm>
+    <glossdef>
+     <para>
+      Not all <glossterm>SQL Objects</glossterm> belong to a certain <glossterm>Schema</glossterm>. Some belong to the complete <glossterm>Database</glossterm>, or even to the complete <glossterm>Cluster</glossterm>. These are referred to as <glossterm>Global SQL Objects</glossterm>. Collations and Extensions such as <glossterm>Foreign Data Wrappers</glossterm> reside at the <glossterm>Database</glossterm> level; <glossterm>Database</glossterm> names, <glossterm>Roles</glossterm>, <glossterm>Tablespaces</glossterm>, <glossterm>Replication</glossterm> origins, and subscriptions for logical <glossterm>Replication</glossterm> at the <glossterm>Cluster</glossterm> level.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-grant">
+    <glossterm>Grant</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command that is used to enable <glossterm>Users</glossterm> or <glossterm>Roles</glossterm> to access specific objects within the <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-grant">SQL Commands: GRANT</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-heap">
+    <glossterm>Heap</glossterm>
+    <glossdef>
+     <para>
+      Contains the original values of <glossterm>Row</glossterm> attributes (i.e. the data). The <glossterm>Heap</glossterm> is realized within <glossterm>Database</glossterm> files and mirrored in <glossterm>Shared Memory</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-host">
+    <glossterm>Host</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Server</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-index">
+    <glossterm>Index</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that contains data derived from a <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> such as a <glossterm>Materialized View</glossterm>). It's internal structure supports very fast retrieval of and access to the original data.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createindex">SQL Commands: CREATE INDEX</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-insert">
+    <glossterm>Insert</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command used to add new data into a <glossterm>Table</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-insert">SQL Commands: INSERT</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-instance">
+    <glossterm>Instance</glossterm>
+    <glossdef>
+     <para>
+      An <glossterm>Instance</glossterm> is a group of processes plus their common <glossterm>Shared Memory</glossterm> running on a single <glossterm>Server</glossterm>. The <glossterm>Instance</glossterm> handles all key features of a <acronym>DBMS</acronym>: read and write access to files and <glossterm>Shared Memory</glossterm>, assurance of the <acronym>ACID</acronym> paradigm, <acronym>MVCC</acronym>, <glossterm>Connections</glossterm> to client programms, backup, recovery, replication, privileges, etc.
+     </para>
+     <para>
+      An <glossterm>Instance</glossterm> manages exactly one <glossterm>Cluster</glossterm>.
+     </para>
+     <para>
+      Many <glossterm>Instances</glossterm> can run on the same server as long as they use different <acronym>IP</acronym> ports and manage different <glossterm>Cluster</glossterm>s. Different <glossterm>Instances</glossterm> on a server may use the same or different versions of <productname>PostgreSQL</productname>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-join">
+    <glossterm>Join</glossterm>
+    <glossdef>
+     <para>
+      A technique used with <command>SELECT</command> statements for correlating data in one or more <glossterm>Relations</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-key">
+    <glossterm>Key</glossterm>
+    <glossdef>
+     <para>
+      A means of identifying a <glossterm>Row</glossterm> within a <glossterm>Table</glossterm> or <glossterm>Relation</glossterm> by values contained within one or more <glossterm>Attributes</glossterm> in that <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-lock">
+    <glossterm>Lock</glossterm>
+    <glossdef>
+     <para>
+      A mechanism for one process temporarily preventing data from being manipulated by any other process.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-file">
+    <glossterm>Log File</glossterm>
+    <glossdef>
+     <para>
+      <link linkend="logfile-maintenance">LOG files</link>
+      contain readable text lines about serious
+      and non-serious events, e.g.: use of
+      wrong password, long-running queries, ... .
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-writer">
+    <glossterm>Log Writer</glossterm>
+    <glossdef>
+     <para>
+      If activated and parameterized, the
+      <link linkend="runtime-config-logging">Log Writer</link>
+      process writes information about database events into the
+      current <glossterm>Log file</glossterm>. When reaching
+      certain time- or volume-dependent criterias, he creates
+      a new <glossterm>Log file</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-record">
+    <glossterm>Log Record</glossterm>
+     <glossdef>
+      <para>
+       See <glossterm>WAL Record</glossterm>.
+      </para>
+     </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-logged">
+    <glossterm>Logged</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Table</glossterm> is considered <glossterm>Logged</glossterm> if changes to the <glossterm>Table</glossterm> are sent to the <glossterm>WAL Log</glossterm>. By default, all regular <glossterm>Tables</glossterm> are <glossterm>Logged</glossterm>. A <glossterm>Table</glossterm> can be speficied as unlogged either at creation time or via the <command>ALTER TABLE</command> command. The primary use of unlogged <glossterm>Tables</glossterm> is for storing transient work data that must be shared across processes, but with a final result stored in logged <glossterm>Tables</glossterm>.  <glossterm>Temporary Tables</glossterm> are always unlogged.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-master">
+    <glossterm>Master</glossterm>
+    <glossdef>
+     <para>
+      When two or more <glossterm>Databases</glossterm> are linked via <glossterm>Replication</glossterm>, the <glossterm>Server</glossterm> that is considered the authoritative source of information is called the <glossterm>Master</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-materialized">
+    <glossterm>Materialized</glossterm>
+    <glossdef>
+     <para>
+      The act of storing information rather than just the means of accessing the information. This term is used in <glossterm>Materialized Views</glossterm> meaning that the data derived from the <glossterm>View</glossterm> is actually stored on disk separate from the sources of that data. When the term <glossterm>Materialized</glossterm> is used in speaking about mulit-step queries, it means that the data of a given step is stored (in memory, but that storage may spill over onto disk).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-materialized-view">
+    <glossterm>Materialized View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that is defined in the same way that a <glossterm>View</glossterm> is, but it stores
+data in the same way that a <glossterm>Table</glossterm> does. it cannot be modified via <command>INSERT</command>, <command>UPDATE</command>, or <command>DELETE</command> operations.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-creatematerializedview">SQL Commands: CREATE MATERIALIZED VIEW</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-null">
+    <glossterm>Null</glossterm>
+    <glossdef>
+     <para>
+      A concept of non-existence that is a central tenet of Relational Database Theory. It represents the absence of value.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-partition">
+    <glossterm>Partition</glossterm>
+    <glossdef>
+     <para>
+      a) A <glossterm>Table</glossterm> that can be queried independently by its own name, but can also be queried via another <glossterm>Table</glossterm>, a partitionend <glossterm>Table</glossterm>, which is a collection of sub-<glossterm>Table</glossterm>s, each capable of holding one defined subset of information that does not overlap with any other <glossterm>Table</glossterm> in the set of <glossterm>Table</glossterm>s.
+     </para>
+     <para>
+      b) A defined boundary used in an <glossterm>Analytic</glossterm> <glossterm>Function</glossterm> to identify which neighboring <glossterm>Rows</glossterm> can be considered by the <glossterm>Function</glossterm> for this particular <glossterm>Row</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-postmaster">
+    <glossterm>Postmaster</glossterm>
+    <glossdef>
+     <para>
+       The very first process of an <glossterm>Instance</glossterm>. It starts the other processes and creates <glossterm>Backend Processes</glossterm> on demand.
+     </para>
+     <para>
+      For more information, see <link linkend="server-start">Server Setup and Operation: Starting the Database Server</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-primary-key">
+    <glossterm>Primary Key</glossterm>
+    <glossdef>
+     <para>
+      A special case of <glossterm>Unique Index</glossterm> defined on a <glossterm>Table</glossterm> or other <glossterm>Relation</glossterm> that also guarantees that all of the <glossterm>Attributes</glossterm> within the <glossterm>Primary Key</glossterm> do not have <glossterm>Null</glossterm> values.  As the name implies, there can be only one <glossterm>Primary Key</glossterm> per <glossterm>Table</glossterm>, though it is possible to have multiple <glossterm>Unique Indexes</glossterm> that also have no <glossterm>Null</glossterm>-capable <glossterm>Attributes</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-procedure">
+    <glossterm>Procedure</glossterm>
+    <glossdef>
+     <para>
+      A defined set of instructions for manipulating data within a <glossterm>Database</glossterm>. <glossterm>Procedure</glossterm> can be written in a variety of programming languages. They may seem similar to <glossterm>Functions</glossterm> but are different in that they must be invoked via the <command>CALL</command> command rather than the <command>SELECT</command> or <command>PERFORM</command> commands, and they are allowed to make transactional statements such as <command>COMMIT</command> and <command>ROLLBACK</command>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createprocedure">SQL Commands: CREATE PROCEDURE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-record">
+    <glossterm>Record</glossterm>
+    <glossdef>
+     <para>
+      See <link linkend="sql-revoke">Tupple</link>.
+     </para>
+     <para>
+      A single <glossterm>Row</glossterm> of a <glossterm>Table</glossterm> or other Relation.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-referential-integrity">
+    <glossterm>Referential Integrity</glossterm>
+    <glossdef>
+     <para>
+      The means of restricting data in one <glossterm>Relation</glossterm> such that it must have matching data in another <glossterm>Relation</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-relation">
+    <glossterm>Relation</glossterm>
+    <glossdef>
+     <para>
+      The generic term for all objects in a <glossterm>Database</glossterm> that have a name and a list of <glossterm>Attributes</glossterm> defined in a specific order. <glossterm>Tables</glossterm>, <glossterm>Views</glossterm>, <glossterm>Foreign Tables</glossterm>, <glossterm>Materialized Views</glossterm>, and <glossterm>Indexes</glossterm> are all <glossterm>Relations</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-replica">
+    <glossterm>Replica</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Database</glossterm> that is paired with a Master <glossterm>Database</glossterm> and is maintaining a copy of some or all of the Master <glossterm>Database</glossterm>'s data. The primary reasons for doing this are to allow for greater access to that data, and to maintain availability of the data in the event that the <glossterm>Master</glossterm> becomes unavailable.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-replication">
+    <glossterm>Replication</glossterm>
+    <glossdef>
+     <para>
+       The act of reproducing data on one <glossterm>Server</glossterm> into another called a <glossterm>Replica</glossterm>. This can take the form of Physical <glossterm>Replication</glossterm>, where all file changes from one <glossterm>Server</glossterm> are copied verbatim, or Logical <glossterm>Replication</glossterm> where a defined subset of data changes are conveyed.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-result-set">
+    <glossterm>Result Set</glossterm>
+    <glossdef>
+     <para>
+      A data structure transmitted from a <glossterm>Server</glossterm> to client program upon the completion of a <acronym>SQL</acronym> command, usually a <command>SELECT</command> but it can be an <command>INSERT</command>, <command>UPDATE</command>, or <command>DELETE</command> command if the <literal>RETURNING</literal> clause is specified. The data structure consists of zero or more <glossterm>Rows</glossterm> with the same ordered set of <glossterm>Attributes</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-revoke">
+    <glossterm>Revoke</glossterm>
+    <glossdef>
+     <para>
+      A command to reduce access to a named set of <glossterm>Database</glossterm> objects for a named list of <glossterm>Users</glossterm> and <glossterm>Roles</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-revoke">SQL Commands: REVOKE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-role">
+    <glossterm>Role</glossterm>
+    <glossdef>
+     <para>
+      A collection of access privileges to the <glossterm>Database</glossterm>. <glossterm>Roles</glossterm> are themselves a privilege that can be granted to other roles. This is often done for convenience or to ensure completeness when multiple Users need the same privileges.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createrole">SQL Commands: CREATE ROLE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-rollback">
+    <glossterm>Rollback</glossterm>
+    <glossdef>
+     <para>
+      A command to undo all of the operations performed since the beginning of a <glossterm>Transaction</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-rollback">SQL Commands: ROLLBACK</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-row">
+    <glossterm>Row</glossterm>
+    <glossdef>
+     <para>
+      See <link linkend="sql-revoke">Tupple</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-savepoint">
+    <glossterm>Savepoint</glossterm>
+    <glossdef>
+     <para>
+      A special mark (such as a timestamp) inside a <glossterm>Transaction</glossterm>. Data modifications after this point in time may be rolled back to the time of the savepoint.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-savepoint">SQL Commands: SAVEPOINT</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-schema">
+    <glossterm>Schema</glossterm>
+    <glossdef>
+     <para>
+      A <link linkend="ddl-schemas">schema</link> is a
+      namespace for <glossterm>SQL objects</glossterm>, which
+      all reside in the same <glossterm>database</glossterm>.
+      Each <glossterm>SQL object</glossterm> must reside in
+      exactly one <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+      In general, the names of <glossterm>SQL objects</glossterm> in the
+      schema are unique - even across different types of objects.
+      The lone exception is the case of <glossterm>Unique</glossterm> <glossterm>Constraint</glossterm>s,
+      in which case there <emphasis>must</emphasis> be a <glossterm>Unique Index</glossterm> with the same name
+      and <glossterm>Schema</glossterm> as the <glossterm>Constraint</glossterm>.
+      There is no restriction on having a name used in multiple <glossterm>Schema</glossterm>s.
+     </para>
+     <para>
+     Many <glossterm>SQL objects</glossterm> reside in the default
+     <glossterm>Schema</glossterm> <literal>public</literal>, but it
+     is expected that more schemas are created to hold application
+     specific <glossterm>SQL objects</glossterm>.
+     </para>
+     <para>
+      More generically, the term <glossterm>Schema</glossterm> is used to mean all data descriptions (<glossterm>Table</glossterm> definitions, <glossterm>Constraint</glossterm>s, comments) for a given <glossterm>Database</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-segment">
+    <glossterm>Segment</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>File Segment</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-select">
+    <glossterm>Select</glossterm>
+    <glossdef>
+     <para>
+      The command used to query a <glossterm>Database</glossterm>. Normally, <command>SELECT</command>s are not expected to modify the <glossterm>Database</glossterm> in any way, but it is possible that <glossterm>Functions</glossterm> invoked within the query could have side-effects that do modify data.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-serializable">
+    <glossterm>Serializable</glossterm>
+    <glossdef>
+     <para>
+      Transactions defined as <literal>SERIALIZABLE</literal> are unable to see changes made within other transactions. In effect, for the initializing session the entire <glossterm>Database</glossterm> appears to be frozen duration such a <glossterm>Transaction</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-server">
+    <glossterm>Server</glossterm>
+    <glossdef>
+     <para>
+      The term <glossterm>Server</glossterm> denotes real hardware, a container, or a Virtual Machine.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-session">
+    <glossterm>Session</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Connection</glossterm> to the <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      A description of the commands that were issued in the life cycle of a particular <glossterm>Connection</glossterm> to the <glossterm>Database</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-sequence">
+    <glossterm>Sequence</glossterm>
+    <glossdef>
+     <para>
+       An <glossterm>Database</glossterm> object which represents the mathematical concept of a numerical integral sequence. It can be thought of as a <glossterm>Table</glossterm> with exactly one <glossterm>Row</glossterm> and one <glossterm>Column</glossterm>. The value stored is known as the current value. A <glossterm>Sequence</glossterm> has a defined direction (almost always increasing) and an interval step (usually 1).  Whenever the <literal>NEXTVAL</literal> pseudo-column of a <glossterm>Sequence</glossterm> is accessed, the curent value is moved in the defined direction by the defined interval step, and that value is returned to the invoking query, and the current value of the sequence is updated to reflect the new value. The value can be updated multiple times in a single query, the net effect being that each row selected will have a different value. Values taken from a <glossterm>Sequence</glossterm> are never reverted even in the case of a <glossterm>Rollback</glossterm>, which means that the <glossterm>Sequence</glossterm> will never emit the same number twice, and thus is the normal way of generating values to be put in a <glossterm>Primary Key</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createsequence">SQL Commands: CREATE SEQUENCE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-shared-memory">
+    <glossterm>Shared Memory</glossterm>
+    <glossdef>
+     <para>
+      <acronym>RAM</acronym> which is used by the processes common to an <glossterm>Instance</glossterm>. It mirrors parts of <glossterm>Database</glossterm> files, provides an area for <glossterm>WAL Records</glossterm>, and stores additional common information. Note that <glossterm>Shared Memory</glossterm> belongs to the complete <glossterm>Instance</glossterm>, not to a single <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      <glossterm>Shared Memory</glossterm> is organized into pages. If a page is modified, it is called a dirty page until it is written back to the file system.
+     </para>
+     <para>
+      For more information, see <link linkend="runtime-config-resource-memory">Server Configuration: Resource Consumption</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-sql-object">
+    <glossterm>SQL Object</glossterm>
+     <glossdef>
+      <para>
+       A <glossterm>Table</glossterm>, <glossterm>View</glossterm>, <glossterm>Materialized View</glossterm>, <glossterm>Index</glossterm>, <glossterm>Constraint</glossterm>, <glossterm>Sequence</glossterm>, <glossterm>Function</glossterm>, <glossterm>Procedure</glossterm>, <glossterm>Trigger</glossterm>, data type, or operator. Every <glossterm>SQL Object</glossterm> belongs to exactly one <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+       For more information, see <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-stats-collector">
+    <glossterm>Stats Collector</glossterm>
+    <glossdef>
+     <para>
+      This process collects statistical information about the <glossterm>Cluster</glossterm>'s activities.
+     </para>
+     <para>
+       For more information, see <link linkend="monitoring-stats">Monitoring Database Activity: The Statistics Collector</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-system-catalog">
+    <glossterm>System Catalog</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Table</glossterm>s and <glossterm>View</glossterm>s which describe the structure of all <acronym>SQL</acronym> objects of the <glossterm>Database</glossterm> and the <glossterm>Global SQL Objects</glossterm> of the <glossterm>Cluster</glossterm>. The <glossterm>System Catalog</glossterm> resides in the schema <literal>pg_catalog</literal>. Main parts are mirrored as <glossterm>Views</glossterm> in the <glossterm>Schema</glossterm> <literal>information_schema</literal>.
+     </para>
+     <para>
+       For more information, see <link linkend="ddl-schemas">Data Definition: Schemas</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-table">
+    <glossterm>Table</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Tuples</glossterm> (also known as <glossterm>Rows</glossterm> or <glossterm>Records</glossterm>) having a common data structure (the same number of <glossterm>Attributes</glossterm>s, in the same order, having the same name and type per position). A <glossterm>Table</glossterm> is the most common form of <glossterm>Relation</glossterm> in <productname>PostgreSQL</productname>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-temporary-tables">
+    <glossterm>Temporary Tables</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>Table</glossterm>s that exist either for the lifetime of a <glossterm>Session</glossterm> or a <glossterm>Transaction</glossterm>, as defined at creation time. The data in them is not visible to other <glossterm>Sessions</glossterm>, and is not <glossterm>Logged</glossterm>. <glossterm>Temporary Tables</glossterm> are most often used to store intermediate data for a multi-step data transformation.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-transaction">
+    <glossterm>Transaction</glossterm>
+    <glossdef>
+     <para>
+      A combination of one or more commands that must act as a single <glossterm>Atomic</glossterm> command: they all succeed or fail together, and their effects are not visible to other sessions until the <glossterm>Transaction</glossterm> is complete.
+     </para>
+     <para>
+      For more information, see <link linkend="transaction-iso">Transaction Isolation</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-trigger">
+    <glossterm>Trigger</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Function</glossterm> which can be defined to execute whenever a certain operation (<command>INSERT</command>, <command>UPDATE</command>, or <command>DELTE</command>) is applied to that <glossterm>Relation</glossterm>. A <glossterm>Trigger</glossterm> executes within the same <glossterm>Transaction</glossterm> as the statement which invoked it, and if the <glossterm>Function</glossterm> fails then the invoking statement also fails.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createtrigger">SQL Commands: CREATE TRIGGER</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-tuple">
+    <glossterm>Tuple</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Attributes</glossterm> in a fixed order. That order may be defined by the <glossterm>Table</glossterm> where the <glossterm>Tuple</glossterm> is found, in which case the <glossterm>Tuple</glossterm> is often called a <glossterm>Row</glossterm> or <glossterm>Record</glossterm>. It may also be defined by the structure of a <glossterm>Result Set</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-unique">
+    <glossterm>Unique</glossterm>
+    <glossdef>
+     <para>
+      The condition of having no matching values in the same <glossterm>Relation</glossterm>. Most often used in the concept of <glossterm>Unique Indexes</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-unlogged">
+    <glossterm>Unlogged</glossterm>
+    <glossdef>
+     <para>
+      Changes to an unlogged <glossterm>Relation</glossterm> are not reflected in the <glossterm>WAL Log</glossterm>.
+      This disables replication and crash recovery for such <glossterm>Relations</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-update">
+    <glossterm>Update</glossterm>
+    <glossdef>
+     <para>
+      A command used to modify <glossterm>Rows</glossterm> that already exist in a specified <glossterm>Table</glossterm>. It
+cannot create <glossterm>Rows</glossterm> nor can it remove <glossterm>Rows</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-update">SQL Commands: UPDATE</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-user">
+    <glossterm>User</glossterm>
+    <glossdef>
+     <para>
+      A specific case of a <glossterm>Role</glossterm> that is entitled to access (log into) the <glossterm>Database</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-user-mapping">
+    <glossterm>User Mapping</glossterm>
+    <glossdef>
+     <para>
+      The translation of user credentials in the local <glossterm>Database</glossterm> to credentials in a remote data system defined by a <glossterm>Foreign Data Wrapper</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createusermapping">SQL Commands: CREATE USER MAPPING</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-view">
+    <glossterm>View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that is defined by a <command>SELECT</command> statement, but has no storage of its own. Any time a query references a <glossterm>View</glossterm>, the definition of the <glossterm>View</glossterm> is substituted into the query as if the user had typed that subquery instead of the name of the <glossterm>View</glossterm>.
+     </para>
+     <para>
+      For more information, see <link linkend="sql-createview">SQL Commands: CREATE VIEW</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-file">
+    <glossterm>WAL File</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>WAL Records</glossterm> are continously written to the end of the current <glossterm>WAL File</glossterm>.  <glossterm>WAL Files</glossterm> as well as <glossterm>WAL Records</glossterm> belong to the complete <glossterm>Cluster</glossterm>, not to a single <glossterm>Database</glossterm>. After a <glossterm>WAL File</glossterm> is full, a new <glossterm>WAL File</glossterm> is created or, under certain conditions, one of the previous <glossterm>WAL Files</glossterm> is renamed and reused.
+     </para>
+     <para>
+      The sequence of <glossterm>WAL Records</glossterm> in combination with the sequence of <glossterm>WAL Files</glossterm> represents the sequence of changes that have taken place in the <glossterm>Cluster</glossterm>.
+     </para>
+      <para>
+       For more information, see <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+    <glossentry id="glossary-wal-log">
+    <glossterm>WAL Log</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-record">
+    <glossterm>WAL Record</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>WAL Record</glossterm> contains either new or changed <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> data or information about a <command>COMMIT</command>, <command>ROLLBACK</command>, <command>SAVEPOINT</command>, or <glossterm>Checkpointer</glossterm> operation. WAL records use a non-printabe binary format.
+     </para>
+      <para>
+       For more information, see <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-segment">
+    <glossterm>WAL Segment</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-segment-file">
+    <glossterm>WAL Segment File</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-writer">
+   <glossterm>WAL Writer</glossterm>
+   <glossdef>
+    <para>
+     This process writes <glossterm>WAL Records</glossterm> from <glossterm>Shared Memory</glossterm> to <glossterm>WAL Files</glossterm>.
+    </para>
+      <para>
+       For more information, see <link linkend="runtime-config-wal">Server Configuration: Write Ahead Log</link>.
+     </para>
+   </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-window-function">
+    <glossterm>Window Function</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Function</glossterm> similar to an <glossterm>Aggregate</glossterm> in that can derive its value
+from a set of <glossterm>Rows</glossterm> in a <glossterm>Result Set</glossterm>, but still retaining the original source
+data.
+     </para>
+     <para>
+      For more information, see <link linkend="tutorial-window">Window Functions</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+  </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index e59cba7997..2183e33bea 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
   &docguide;
   &limits;
   &acronyms;
+  &glossary;
 
  </part>
 
-- 
2.20.1

From 72f7a425fcd9a803010294e6974ecd7680a9aee6 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 19 Mar 2020 18:29:12 -0300
Subject: [PATCH 1/2] glossary

---
 doc/src/sgml/filelist.sgml |    1 +
 doc/src/sgml/glossary.sgml | 1441 ++++++++++++++++++++++++++++++++++++
 doc/src/sgml/postgres.sgml |    1 +
 3 files changed, 1443 insertions(+)
 create mode 100644 doc/src/sgml/glossary.sgml

diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 3da2365ea9..504c8a6326 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY glossary   SYSTEM "glossary.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..cf20fb759c
--- /dev/null
+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,1441 @@
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+  This is a list of terms and their meaning in the context of
+  <productname>PostgreSQL</productname> and relational database
+  systems in general.
+ </para>
+  <glosslist>
+   <glossentry id="glossary-aggregate">
+    <glossterm>Aggregate</glossterm>
+    <glossdef>
+     <para>
+      To combine a collection of data values into a single value, whose
+      value may not be of the same type as the original values.
+      <glossterm>Aggregate</glossterm> <glossterm>Functions</glossterm>
+      combine multiple <glossterm>Rows</glossterm> that share a common set
+      of values into one <glossterm>Row</glossterm>, which means that the
+      only data visible in the values in common, and the aggregates of the
+      non-common data.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="functions-aggregate">Aggregate Functions</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-analytic">
+    <glossterm>Analytic</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Function</glossterm> whose computed value can reference
+      values found in nearby <glossterm>Rows</glossterm> of the same
+      <glossterm>Result Set</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="tutorial-window">Window Functions</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-archiver">
+    <glossterm>Archiver</glossterm>
+    <glossdef>
+     <para>
+      A process that backs up <glossterm>WAL Files</glossterm> in order to
+      reclaim space on the file system.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="continuous-archiving">Backup and Restore: Continuous Archiving and Point-in-Time Recovery (PITR)</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-atomic">
+    <glossterm>Atomic</glossterm>
+    <glossdef>
+     <para>
+      In reference to the value of an <glossterm>Attribute</glossterm> or
+      <glossterm>Datum</glossterm>: cannot be broken down into smaller
+      components.
+     </para>
+     <para>
+      In reference to an operation: An event that cannot be completed in
+      part: it must either entirely succeed or entirely fail. A series of
+      <acronym>SQL</acronym> statements can be combined into a
+      <glossterm>Transaction</glossterm>, and that
+      <glossterm>transaction</glossterm> is said to be
+      <glossterm>Atomic</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-attribute">
+    <glossterm>Attribute</glossterm>
+    <glossdef>
+     <para>
+      An element with a certain name and data type found within a
+      <glossterm>Tuple</glossterm> or <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-autovacuum">
+    <glossterm>Autovacuum</glossterm>
+    <glossdef>
+     <para>
+      Processes that remove outdated <acronym>MVCC</acronym>
+      <glossterm>Records</glossterm> of the <glossterm>Heap</glossterm> and
+      <glossterm>Index</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="routine-vacuuming">Routine Database Maintenance Tasks: Routine Vacuuming</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-backend-process">
+    <glossterm>Backend Process</glossterm>
+    <glossdef>
+     <para>
+      Processes of an <glossterm>Instance</glossterm> which act on behalf of
+      client <glossterm>Connections</glossterm> and handle their requests.
+     </para>
+     <para>
+      (Don't confuse this term with the similar terms <glossterm>Background
+      Worker</glossterm> or <glossterm>Background Writer</glossterm>).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-backend-server">
+    <glossterm>Backend Server</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Instance</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-background-worker">
+    <glossterm>Background Worker</glossterm>
+    <glossdef>
+     <para>
+      Individual processes within an <glossterm>Instance</glossterm>, which
+      run system- or user-supplied code. Typical use cases are processes
+      which handle parts of an <acronym>SQL</acronym> query to take
+      advantage of parallel execution on servers with multiple
+      <acronym>CPUs</acronym>.
+    </para>
+    <para>
+     For more information, see
+     <link linkend="bgworker">Background Worker Processes</link>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-background-writer">
+    <glossterm>Background Writer</glossterm>
+    <glossdef>
+     <para>
+      Writes continuously dirty pages from <glossterm>Shared
+      Memory</glossterm> to the file system. It starts periodically, but
+      works only for a short period in order to distribute expensive
+      <acronym>I/O</acronym> activity over time instead of generating fewer
+      large <acronym>I/O</acronym> peaks which could block other processes.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="runtime-config-resource">Server Configuration: Resource Consumption</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-cast">
+    <glossterm>Cast</glossterm>
+    <glossdef>
+     <para>
+      A conversion of a <glossterm>Datum</glossterm> from its current data
+      type to another data type.
+     </para>
+    </glossdef>
+   </glossentry>
+
+ <glossentry id="glossary-catalog">
+    <glossterm>Catalog</glossterm>
+    <glossdef>
+     <para>
+      The <acronym>SQL</acronym> standard uses this standalone term to
+      indicate what is called a <glossterm>Database</glossterm> in
+      <productname>PostgreSQL</productname>'s terminology.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-check-constraint">
+    <glossterm>Check Constraint</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Constraint</glossterm> defined on a
+      <glossterm>Relation</glossterm> which restricts the values allowed in
+      one or more <glossterm>Attributes</glossterm>. The <glossterm>Check
+      Constraint</glossterm> can make reference to any
+      <glossterm>Attribute</glossterm> in the
+      <glossterm>Relation</glossterm>, but cannot reference other
+      <glossterm>Rows</glossterm> of the same
+      <glossterm>Relation</glossterm> or other
+      <glossterm>Relations</glossterm>.
+     </para>
+    <para>
+     For more information, see
+     <link linkend="ddl-constraints">Constraints</link>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-checkpointer">
+    <glossterm>Checkpointer</glossterm>
+    <glossdef>
+     <para>
+      A process that writes dirty pages and <glossterm>WAL
+      Records</glossterm> to the file system and creates a special
+      checkpoint record. This process is initiated when predefined
+      conditions are met, such as a specified amount of time has passed, or
+      a certain volume of records have been collected.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-checkpoint">
+    <glossterm>Checkpoint</glossterm>
+    <glossdef>
+     <para>
+      A <link linkend="sql-checkpoint"> Checkpoint</link> is a point in time
+      when all older dirty pages of the <glossterm>Shared
+      Memory</glossterm>, all older <glossterm>WAL records</glossterm>, and
+      a special <glossterm>Checkpoint record</glossterm> have been written
+      and flushed to disk.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-cluster">
+    <glossterm>Cluster</glossterm>
+    <glossdef>
+     <para>
+      A group of <glossterm>Database</glossterm>s plus their
+      <glossterm>Global SQL Objects</glossterm>. The
+      <glossterm>Cluster</glossterm> is managed by exactly one
+      <glossterm>Instance</glossterm>. A newly created
+      <glossterm>Cluster</glossterm> will have three
+      <glossterm>Databases</glossterm> created automatically. They are
+      <literal>template0</literal>, <literal>template1</literal>, and
+      <literal>postgres</literal>. It is expected that an application will
+      create one or more additional <glossterm>Databases</glossterm> aside
+      from these three.
+     </para>
+     <para>
+      Don't confuse the <productname>PostgreSQL</productname> specific term
+      <glossterm>Cluster</glossterm> with the SQL command
+      <literal>CLUSTER</literal>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-column">
+    <glossterm>Column</glossterm>
+    <glossdef>
+     <para>
+      An <glossterm>Attribute</glossterm> found in a
+      <glossterm>Table</glossterm> or <glossterm>View</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-commit">
+    <glossterm>Commit</glossterm>
+    <glossdef>
+     <para>
+      The act of finalizing a <glossterm>Transaction</glossterm> within the
+      <glossterm>Database</glossterm>.
+     </para>
+    <para>
+     For more information, see
+     <link linkend="sql-commit">SQL Commands: COMMIT</link>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-concurrency">
+    <glossterm>Concurrency</glossterm>
+    <glossdef>
+     <para>
+      The concept that multiple independent operations happen within the
+      <glossterm>Database</glossterm> at the same time.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-connection">
+    <glossterm>Connection</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>TCP/IP</acronym> or socket line for inter-process
+      communication. If the two involved processes reside on different
+      servers, <acronym>TCP/IP</acronym> must be used.  Otherwise both
+      techniques are possible.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-constraint">
+    <glossterm>Constraint</glossterm>
+    <glossdef>
+     <para>
+      A concept of restricting the values of data allowed within a
+      <glossterm>Table</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="ddl-constraints">Constraints</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-data-area">
+    <glossterm>Data Area</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Data Directory</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-data-directory">
+    <glossterm>Data Directory</glossterm>
+    <glossdef>
+     <para>
+      The base directory on the filesystem of a
+      <glossterm>Server</glossterm> that contains all data files and
+      subdirectories associated with a <glossterm>Cluster</glossterm> with
+      the exception of tablespaces. The environment variable
+      <literal>PGDATA</literal> often &mdash; but not always &mdash; referes to the
+      <glossterm>Data Directory</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-database">
+    <glossterm>Database</glossterm>
+    <glossdef>
+     <para>
+      A named collection of <glossterm>SQL Objects</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-database-server">
+    <glossterm>Database Server</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Instance</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-datum">
+    <glossterm>Datum</glossterm>
+    <glossdef>
+     <para>
+      The internal representation of a <acronym>SQL</acronym> data type.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-delete">
+    <glossterm>Delete</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command whose purpose is to remove
+      <glossterm>Rows</glossterm> from a given <glossterm>Table</glossterm>
+      or <glossterm>Relation</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-delete">SQL Commands: DELETE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-file-segment">
+    <glossterm>File Segment</glossterm>
+    <glossdef>
+     <para>
+       If a heap or index file grows in size over 1 GB, it will be split
+       into multiple physical files. These files are called <glossterm>File
+       Segments</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+     </para>
+     <para>
+      (Don't confuse this term with the similar term
+      <glossterm>WAL Segment</glossterm>).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-data-wrapper">
+    <glossterm>Foreign Data Wrapper</glossterm>
+    <glossdef>
+     <para>
+      A means of representing data that is not contained in the local
+      <glossterm>Database</glossterm> as if were in local
+      <glossterm>Table</glossterm>(s). With a Foreign Data Wrapper it is
+      possible to define a <glossterm>Foreign Server</glossterm> and
+      <glossterm>Foreign Tables</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createforeigndatawrapper">SQL Commands: CREATE FOREIGN DATA WRAPPER</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-key">
+    <glossterm>Foreign Key</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Constraint</glossterm> defined on one or more
+      <glossterm>Column</glossterm>s in a <glossterm>Table</glossterm> which
+      requires the value in those <glossterm>Column</glossterm>s to uniquely
+      identify a <glossterm>Row</glossterm> in the specified
+      <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-server">
+    <glossterm>Foreign Server</glossterm>
+    <glossdef>
+     <para>
+      A named collection of <glossterm>Foreign Tables</glossterm> which all
+      use the same <glossterm>Foreign Data Wrapper</glossterm> and have
+      other configuration values in common.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createserver">SQL Commands: CREATE SERVER</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-table">
+    <glossterm>Foreign Table</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> which appears to have
+      <glossterm>Rows</glossterm> and <glossterm>Columns</glossterm> similar
+      to a regular <glossterm>Table</glossterm>, but will forward requests
+      for data through its <glossterm>Foreign Data Wrapper</glossterm>,
+      which will return <glossterm>Result Sets</glossterm> structured
+      according to the definition of the <glossterm>Foreign Table</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createforeigntable">SQL Commands: CREATE FOREIGN TABLE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-function">
+    <glossterm>Function</glossterm>
+    <glossdef>
+     <para>
+      Any pre-defined transformation of data. Many
+      <glossterm>Functions</glossterm> are already defined within
+      <productname>PostgreSQL</productname> itself, but can also be
+      user-defined.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createfunction">SQL Commands: CREATE FUNCTION</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-global-sql-object">
+    <glossterm>Global SQL Object</glossterm>
+    <glossdef>
+     <para>
+     <!-- FIXME -->
+      Not all <glossterm>SQL Objects</glossterm> belong to a certain
+      <glossterm>Schema</glossterm>. Some belong to the complete
+      <glossterm>Database</glossterm>, or even to the complete
+      <glossterm>Cluster</glossterm>. These are referred to as
+      <glossterm>Global SQL Objects</glossterm>. Collations and Extensions
+      such as <glossterm>Foreign Data Wrappers</glossterm> reside at the
+      <glossterm>Database</glossterm> level; <glossterm>Database</glossterm>
+      names, <glossterm>Roles</glossterm>,
+      <glossterm>Tablespaces</glossterm>, <glossterm>Replication</glossterm>
+      origins, and subscriptions for logical
+      <glossterm>Replication</glossterm> at the
+      <glossterm>Cluster</glossterm> level.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-grant">
+    <glossterm>Grant</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command that is used to enable
+      <glossterm>Users</glossterm> or <glossterm>Roles</glossterm> to access
+      specific objects within the <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-grant">SQL Commands: GRANT</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-heap">
+    <glossterm>Heap</glossterm>
+    <glossdef>
+     <para>
+      Contains the original values of <glossterm>Row</glossterm> attributes
+      (i.e. the data). The <glossterm>Heap</glossterm> is realized within
+      <glossterm>Database</glossterm> files and mirrored in
+      <glossterm>Shared Memory</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-host">
+    <glossterm>Host</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Server</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-index">
+    <glossterm>Index</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that contains data derived from a
+      <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> such
+      as a <glossterm>Materialized View</glossterm>). It's internal
+      structure supports very fast retrieval of and access to the original
+      data.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createindex">SQL Commands: CREATE INDEX</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-insert">
+    <glossterm>Insert</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command used to add new data into a
+      <glossterm>Table</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-insert">SQL Commands: INSERT</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-instance">
+    <glossterm>Instance</glossterm>
+    <glossdef>
+     <para>
+      An <glossterm>Instance</glossterm> is a group of processes plus their
+      common <glossterm>Shared Memory</glossterm> running on a single
+      <glossterm>Server</glossterm>. The <glossterm>Instance</glossterm>
+      handles all key features of a <acronym>DBMS</acronym>: read and write
+      access to files and <glossterm>Shared Memory</glossterm>, assurance of
+      the <acronym>ACID</acronym> paradigm, <acronym>MVCC</acronym>,
+      <glossterm>Connections</glossterm> to client programms, backup,
+      recovery, replication, privileges, etc.
+     </para>
+     <para>
+      An <glossterm>Instance</glossterm> manages exactly one
+      <glossterm>Cluster</glossterm>.
+     </para>
+     <para>
+      Many <glossterm>Instances</glossterm> can run on the same server as
+      long as they use different <acronym>IP</acronym> ports and manage
+      different <glossterm>Cluster</glossterm>s. Different
+      <glossterm>Instances</glossterm> on a server may use the same or
+      different versions of <productname>PostgreSQL</productname>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-join">
+    <glossterm>Join</glossterm>
+    <glossdef>
+     <para>
+      A technique used with <command>SELECT</command> statements for
+      correlating data in one or more <glossterm>Relations</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-key">
+    <glossterm>Key</glossterm>
+    <glossdef>
+     <para>
+      A means of identifying a <glossterm>Row</glossterm> within a
+      <glossterm>Table</glossterm> or <glossterm>Relation</glossterm> by
+      values contained within one or more <glossterm>Attributes</glossterm>
+      in that <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-lock">
+    <glossterm>Lock</glossterm>
+    <glossdef>
+     <para>
+      A mechanism for one process temporarily preventing data from being
+      manipulated by any other process.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-file">
+    <glossterm>Log File</glossterm>
+    <glossdef>
+     <para>
+      <link linkend="logfile-maintenance">LOG files</link> contain readable
+      text lines about serious and non-serious events, e.g.: use of wrong
+      password, long-running queries, ... .
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-writer">
+    <glossterm>Log Writer</glossterm>
+    <glossdef>
+     <para>
+      If activated and parameterized, the
+      <link linkend="runtime-config-logging">Log Writer</link> process
+      writes information about database events into the current
+      <glossterm>Log file</glossterm>. When reaching certain time- or
+      volume-dependent criterias, he <!-- FIXME "he"? --> creates a new
+      <glossterm>Log file</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-record">
+    <glossterm>Log Record</glossterm>
+     <glossdef>
+      <para>
+       See <glossterm>WAL Record</glossterm>.
+      </para>
+     </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-logged">
+    <glossterm>Logged</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Table</glossterm> is considered
+      <glossterm>Logged</glossterm> if changes to it are sent to the
+      <glossterm>WAL Log</glossterm>. By default, all regular
+      <glossterm>Tables</glossterm> are <glossterm>Logged</glossterm>. A
+      <glossterm>Table</glossterm> can be speficied as unlogged either at
+      creation time or via the <command>ALTER TABLE</command> command. The
+      primary use of unlogged <glossterm>Tables</glossterm> is for storing
+      transient work data that must be shared across processes, but with a
+      final result stored in logged <glossterm>Tables</glossterm>.
+      <glossterm>Temporary Tables</glossterm> are always unlogged.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-master">
+    <glossterm>Master</glossterm>
+    <glossdef>
+     <para>
+      When two or more <glossterm>Databases</glossterm> are linked via
+      <glossterm>Replication</glossterm>, the <glossterm>Server</glossterm>
+      that is considered the authoritative source of information is called
+      the <glossterm>Master</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-materialized">
+    <glossterm>Materialized</glossterm>
+    <glossdef>
+     <para>
+      The act of storing information rather than just the means of accessing
+      the information. This term is used in <glossterm>Materialized
+      Views</glossterm> meaning that the data derived from the
+      <glossterm>View</glossterm> is actually stored on disk separate from
+      the sources of that data. When the term
+      <glossterm>Materialized</glossterm> is used in speaking about
+      mulit-step queries, it means that the data of a given step is stored
+      (in memory, but that storage may spill over onto disk).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-materialized-view">
+    <glossterm>Materialized View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that is defined in the same way that
+      a <glossterm>View</glossterm> is, but it stores data in the same way
+      that a <glossterm>Table</glossterm> does. it cannot be modified via
+      <command>INSERT</command>, <command>UPDATE</command>, or
+      <command>DELETE</command> operations.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-creatematerializedview">SQL Commands: CREATE MATERIALIZED VIEW</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-null">
+    <glossterm>Null</glossterm>
+    <glossdef>
+     <para>
+      A concept of non-existence that is a central tenet of Relational
+      Database Theory. It represents the absence of value.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-partition">
+    <glossterm>Partition</glossterm>
+    <glossdef>
+     <para>
+      <!-- FIXME should this use the style used in "atomic"? -->
+      a) A <glossterm>Table</glossterm> that can be queried independently by
+      its own name, but can also be queried via another
+      <glossterm>Table</glossterm>, a partitionend
+      <glossterm>Table</glossterm>, which is a collection of
+      sub-<glossterm>Table</glossterm>s, each capable of holding one defined
+      subset of information that does not overlap with any other
+      <glossterm>Table</glossterm> in the set of
+      <glossterm>Table</glossterm>s.
+     </para>
+     <para>
+      b) A defined boundary used in an <glossterm>Analytic</glossterm>
+      <glossterm>Function</glossterm> to identify which neighboring
+      <glossterm>Rows</glossterm> can be considered by the
+      <glossterm>Function</glossterm> for this particular
+      <glossterm>Row</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-postmaster">
+    <glossterm>Postmaster</glossterm>
+    <glossdef>
+     <para>
+       The very first process of an <glossterm>Instance</glossterm>. It
+       starts the other processes and creates <glossterm>Backend
+       Processes</glossterm> on demand.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="server-start">Server Setup and Operation: Starting the Database Server</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-primary-key">
+    <glossterm>Primary Key</glossterm>
+    <glossdef>
+     <para>
+      A special case of <glossterm>Unique Index</glossterm> defined on a
+      <glossterm>Table</glossterm> or other <glossterm>Relation</glossterm>
+      that also guarantees that all of the <glossterm>Attributes</glossterm>
+      within the <glossterm>Primary Key</glossterm> do not have
+      <glossterm>Null</glossterm> values.  As the name implies, there can be
+      only one <glossterm>Primary Key</glossterm> per
+      <glossterm>Table</glossterm>, though it is possible to have multiple
+      <glossterm>Unique Indexes</glossterm> that also have no
+      <glossterm>Null</glossterm>-capable <glossterm>Attributes</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-procedure">
+    <glossterm>Procedure</glossterm>
+    <glossdef>
+     <para>
+      A defined set of instructions for manipulating data within a
+      <glossterm>Database</glossterm>. <glossterm>Procedure</glossterm> can
+      be written in a variety of programming languages. They may seem
+      similar to <glossterm>Functions</glossterm> but are different in that
+      they must be invoked via the <command>CALL</command> command rather
+      than the <command>SELECT</command> or <command>PERFORM</command>
+      commands, and they are allowed to make transactional statements such
+      as <command>COMMIT</command> and <command>ROLLBACK</command>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createprocedure">SQL Commands: CREATE PROCEDURE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-record">
+    <glossterm>Record</glossterm>
+    <glossdef>
+     <para>
+      See <link linkend="sql-revoke">Tupple</link>.
+     </para>
+     <para>
+      A single <glossterm>Row</glossterm> of a <glossterm>Table</glossterm>
+      or other Relation.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-referential-integrity">
+    <glossterm>Referential Integrity</glossterm>
+    <glossdef>
+     <para>
+      The means of restricting data in one <glossterm>Relation</glossterm>
+      such that it must have matching data in another
+      <glossterm>Relation</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-relation">
+    <glossterm>Relation</glossterm>
+    <glossdef>
+     <para>
+      The generic term for all objects in a <glossterm>Database</glossterm>
+      that have a name and a list of <glossterm>Attributes</glossterm>
+      defined in a specific order. <glossterm>Tables</glossterm>,
+      <glossterm>Views</glossterm>, <glossterm>Foreign Tables</glossterm>,
+      <glossterm>Materialized Views</glossterm>, and
+      <glossterm>Indexes</glossterm> are all
+      <glossterm>Relations</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-replica">
+    <glossterm>Replica</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Database</glossterm> that is paired with a Master
+      <glossterm>Database</glossterm> and is maintaining a copy of some or
+      all of the Master <glossterm>Database</glossterm>'s data. The primary
+      reasons for doing this are to allow for greater access to that data,
+      and to maintain availability of the data in the event that the
+      <glossterm>Master</glossterm> becomes unavailable.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-replication">
+    <glossterm>Replication</glossterm>
+    <glossdef>
+     <para>
+       The act of reproducing data on one <glossterm>Server</glossterm> into
+       another called a <glossterm>Replica</glossterm>. This can take the
+       form of Physical <glossterm>Replication</glossterm>, where all file
+       changes from one <glossterm>Server</glossterm> are copied verbatim,
+       or Logical <glossterm>Replication</glossterm> where a defined subset
+       of data changes are conveyed.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-result-set">
+    <glossterm>Result Set</glossterm>
+    <glossdef>
+     <para>
+      A data structure transmitted from a <glossterm>Server</glossterm> to
+      client program upon the completion of a <acronym>SQL</acronym>
+      command, usually a <command>SELECT</command> but it can be an
+      <command>INSERT</command>, <command>UPDATE</command>, or
+      <command>DELETE</command> command if the <literal>RETURNING</literal>
+      clause is specified. The data structure consists of zero or more
+      <glossterm>Rows</glossterm> with the same ordered set of
+      <glossterm>Attributes</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-revoke">
+    <glossterm>Revoke</glossterm>
+    <glossdef>
+     <para>
+      A command to reduce access to a named set of
+      <glossterm>Database</glossterm> objects for a named list of
+      <glossterm>Users</glossterm> and <glossterm>Roles</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-revoke">SQL Commands: REVOKE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-role">
+    <glossterm>Role</glossterm>
+    <glossdef>
+     <para>
+      A collection of access privileges to the
+      <glossterm>Database</glossterm>. <glossterm>Roles</glossterm> are
+      themselves a privilege that can be granted to other roles. This is
+      often done for convenience or to ensure completeness when multiple
+      Users need the same privileges.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createrole">SQL Commands: CREATE ROLE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-rollback">
+    <glossterm>Rollback</glossterm>
+    <glossdef>
+     <para>
+      A command to undo all of the operations performed since the beginning
+      of a <glossterm>Transaction</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-rollback">SQL Commands: ROLLBACK</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-row">
+    <glossterm>Row</glossterm>
+    <glossdef>
+     <para>
+      See <link linkend="sql-revoke">Tupple</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-savepoint">
+    <glossterm>Savepoint</glossterm>
+    <glossdef>
+     <para>
+      A special mark (such as a timestamp) inside a
+      <glossterm>Transaction</glossterm>. Data modifications after this
+      point in time may be rolled back to the time of the savepoint.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-savepoint">SQL Commands: SAVEPOINT</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-schema">
+    <glossterm>Schema</glossterm>
+    <glossdef>
+     <para>
+      A <link linkend="ddl-schemas">schema</link> is a namespace for
+      <glossterm>SQL objects</glossterm>, which all reside in the same
+      <glossterm>database</glossterm>.  Each <glossterm>SQL
+      object</glossterm> must reside in exactly one
+      <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+      In general, the names of <glossterm>SQL objects</glossterm> in the
+      schema are unique - even across different types of objects.  The lone
+      exception is the case of <glossterm>Unique</glossterm>
+      <glossterm>Constraint</glossterm>s, in which case there
+      <emphasis>must</emphasis> be a <glossterm>Unique Index</glossterm>
+      with the same name and <glossterm>Schema</glossterm> as the
+      <glossterm>Constraint</glossterm>.  There is no restriction on having
+      a name used in multiple <glossterm>Schema</glossterm>s.
+     </para>
+     <para>
+      Many <glossterm>SQL objects</glossterm> reside in the default
+      <glossterm>Schema</glossterm> <literal>public</literal>, but it is
+      expected that more schemas are created to hold application specific
+      <glossterm>SQL objects</glossterm>.
+     </para>
+     <para>
+      More generically, the term <glossterm>Schema</glossterm> is used to
+      mean all data descriptions (<glossterm>Table</glossterm> definitions,
+      <glossterm>Constraint</glossterm>s, comments) for a given
+      <glossterm>Database</glossterm>.  </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-segment">
+    <glossterm>Segment</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>File Segment</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-select">
+    <glossterm>Select</glossterm>
+    <glossdef>
+     <para>
+      The command used to query a <glossterm>Database</glossterm>. Normally,
+      <command>SELECT</command>s are not expected to modify the
+      <glossterm>Database</glossterm> in any way, but it is possible that
+      <glossterm>Functions</glossterm> invoked within the query could have
+      side-effects that do modify data.  </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-serializable">
+    <glossterm>Serializable</glossterm>
+    <glossdef>
+     <para>
+      Transactions defined as <literal>SERIALIZABLE</literal> are unable to
+      see changes made within other transactions. In effect, for the
+      initializing session the entire <glossterm>Database</glossterm>
+      appears to be frozen duration such a
+      <glossterm>Transaction</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-server">
+    <glossterm>Server</glossterm>
+    <glossdef>
+     <para>
+      The term <glossterm>Server</glossterm> denotes real hardware, a
+      container, or a Virtual Machine.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-session">
+    <glossterm>Session</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Connection</glossterm> to the <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      A description of the commands that were issued in the life cycle of a
+      particular <glossterm>Connection</glossterm> to the
+      <glossterm>Database</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-sequence">
+    <glossterm>Sequence</glossterm>
+    <glossdef>
+     <para>
+      <!-- sounds excessively complicated a definition -->
+      An <glossterm>Database</glossterm> object which represents the
+      mathematical concept of a numerical integral sequence. It can be
+      thought of as a <glossterm>Table</glossterm> with exactly one
+      <glossterm>Row</glossterm> and one <glossterm>Column</glossterm>. The
+      value stored is known as the current value. A
+      <glossterm>Sequence</glossterm> has a defined direction (almost always
+      increasing) and an interval step (usually 1).  Whenever the
+      <literal>NEXTVAL</literal> pseudo-column of a
+      <glossterm>Sequence</glossterm> is accessed, the current value is moved
+      in the defined direction by the defined interval step, and that value
+      is returned to the invoking query, and the current value of the
+      sequence is updated to reflect the new value. The value can be updated
+      multiple times in a single query, the net effect being that each row
+      selected will have a different value. Values taken from a
+      <glossterm>Sequence</glossterm> are never reverted even in the case of
+      a <glossterm>Rollback</glossterm>, which means that the
+      <glossterm>Sequence</glossterm> will never emit the same number twice,
+      and thus is the normal way of generating values to be put in a
+      <glossterm>Primary Key</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createsequence">SQL Commands: CREATE SEQUENCE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-shared-memory">
+    <glossterm>Shared Memory</glossterm>
+    <glossdef>
+     <para>
+      <acronym>RAM</acronym> which is used by the processes common to an
+      <glossterm>Instance</glossterm>. It mirrors parts of
+      <glossterm>Database</glossterm> files, provides an area for
+      <glossterm>WAL Records</glossterm>, and stores additional common
+      information. Note that <glossterm>Shared Memory</glossterm> belongs to
+      the complete <glossterm>Instance</glossterm>, not to a single
+      <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      <glossterm>Shared Memory</glossterm> is organized into pages. If a
+      page is modified, it is called a dirty page until it is written back
+      to the file system.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="runtime-config-resource-memory">Server Configuration: Resource Consumption</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-sql-object">
+    <glossterm>SQL Object</glossterm>
+     <glossdef>
+      <para>
+      <!-- FIXME why enumerate each type? -->
+       A <glossterm>Table</glossterm>, <glossterm>View</glossterm>,
+       <glossterm>Materialized View</glossterm>,
+       <glossterm>Index</glossterm>, <glossterm>Constraint</glossterm>,
+       <glossterm>Sequence</glossterm>, <glossterm>Function</glossterm>,
+       <glossterm>Procedure</glossterm>, <glossterm>Trigger</glossterm>,
+       data type, or operator. Every <glossterm>SQL Object</glossterm>
+       belongs to exactly one <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+       For more information, see
+       <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-stats-collector">
+    <glossterm>Stats Collector</glossterm>
+    <glossdef>
+     <para>
+      This process collects statistical information about the
+      <glossterm>Cluster</glossterm>'s activities.
+     </para>
+     <para>
+       For more information, see
+       <link linkend="monitoring-stats">Monitoring Database Activity: The Statistics Collector</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-system-catalog">
+    <glossterm>System Catalog</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Table</glossterm>s and
+      <glossterm>View</glossterm>s which describe the structure of all
+      <acronym>SQL</acronym> objects of the <glossterm>Database</glossterm>
+      and the <glossterm>Global SQL Objects</glossterm> of the
+      <glossterm>Cluster</glossterm>. The <glossterm>System
+      Catalog</glossterm> resides in the schema
+      <literal>pg_catalog</literal>. Main parts are mirrored as
+      <glossterm>Views</glossterm> in the <glossterm>Schema</glossterm>
+      <literal>information_schema</literal>.
+     </para>
+     <para>
+       For more information, see
+       <link linkend="ddl-schemas">Data Definition: Schemas</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-table">
+    <glossterm>Table</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Tuples</glossterm> (also known as
+      <glossterm>Rows</glossterm> or <glossterm>Records</glossterm>) having
+      a common data structure (the same number of
+      <glossterm>Attributes</glossterm>s, in the same order, having the same
+      name and type per position). A <glossterm>Table</glossterm> is the
+      most common form of <glossterm>Relation</glossterm> in
+      <productname>PostgreSQL</productname>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-temporary-tables">
+    <glossterm>Temporary Tables</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>Table</glossterm>s that exist either for the lifetime of a
+      <glossterm>Session</glossterm> or a
+      <glossterm>Transaction</glossterm>, as defined at creation time. The
+      data in them is not visible to other <glossterm>Sessions</glossterm>,
+      and is not <glossterm>Logged</glossterm>. <glossterm>Temporary
+      Tables</glossterm> are most often used to store intermediate data for
+      a multi-step data transformation.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-transaction">
+    <glossterm>Transaction</glossterm>
+    <glossdef>
+     <para>
+      A combination of one or more commands that must act as a single
+      <glossterm>Atomic</glossterm> command: they all succeed or fail
+      together, and their effects are not visible to other sessions until
+      the <glossterm>Transaction</glossterm> is complete.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="transaction-iso">Transaction Isolation</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-trigger">
+    <glossterm>Trigger</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Function</glossterm> which can be defined to execute
+      whenever a certain operation (<command>INSERT</command>,
+      <command>UPDATE</command>, or <command>DELTE</command>) is applied to
+      that <glossterm>Relation</glossterm>. A <glossterm>Trigger</glossterm>
+      executes within the same <glossterm>Transaction</glossterm> as the
+      statement which invoked it, and if the <glossterm>Function</glossterm>
+      fails then the invoking statement also fails.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createtrigger">SQL Commands: CREATE TRIGGER</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-tuple">
+    <glossterm>Tuple</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Attributes</glossterm> in a fixed order.
+      That order may be defined by the <glossterm>Table</glossterm> where
+      the <glossterm>Tuple</glossterm> is found, in which case the
+      <glossterm>Tuple</glossterm> is often called a
+      <glossterm>Row</glossterm> or <glossterm>Record</glossterm>. It may
+      also be defined by the structure of a <glossterm>Result
+      Set</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-unique">
+    <glossterm>Unique</glossterm>
+    <glossdef>
+     <para>
+      The condition of having no matching values in the same
+      <glossterm>Relation</glossterm>. Most often used in the concept of
+      <glossterm>Unique Indexes</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-unlogged">
+    <glossterm>Unlogged</glossterm>
+    <glossdef>
+     <para>
+      Changes to an unlogged <glossterm>Relation</glossterm> are not
+      reflected in the <glossterm>WAL Log</glossterm>.  This disables
+      replication and crash recovery for such <glossterm>Relations</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-update">
+    <glossterm>Update</glossterm>
+    <glossdef>
+     <para>
+      A command used to modify <glossterm>Rows</glossterm> that already
+      exist in a specified <glossterm>Table</glossterm>. It cannot create
+      <glossterm>Rows</glossterm> nor can it remove
+      <glossterm>Rows</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-update">SQL Commands: UPDATE</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-user">
+    <glossterm>User</glossterm>
+    <glossdef>
+     <para>
+      A specific case of a <glossterm>Role</glossterm> that is entitled to
+      access (log into) the <glossterm>Database</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-user-mapping">
+    <glossterm>User Mapping</glossterm>
+    <glossdef>
+     <para>
+      The translation of user credentials in the local
+      <glossterm>Database</glossterm> to credentials in a remote data system
+      defined by a <glossterm>Foreign Data Wrapper</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createusermapping">SQL Commands: CREATE USER MAPPING</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-view">
+    <glossterm>View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that is defined by a
+      <command>SELECT</command> statement, but has no storage of its own.
+      Any time a query references a <glossterm>View</glossterm>, the
+      definition of the <glossterm>View</glossterm> is substituted into the
+      query as if the user had typed that subquery instead of the name of
+      the <glossterm>View</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="sql-createview">SQL Commands: CREATE VIEW</link>
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-file">
+    <glossterm>WAL File</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>WAL Records</glossterm> are continously written to the end
+      of the current <glossterm>WAL File</glossterm>.  <glossterm>WAL
+      Files</glossterm> as well as <glossterm>WAL Records</glossterm> belong
+      to the complete <glossterm>Cluster</glossterm>, not to a single
+      <glossterm>Database</glossterm>. After a <glossterm>WAL
+      File</glossterm> is full, a new <glossterm>WAL File</glossterm> is
+      created or, under certain conditions, one of the previous
+      <glossterm>WAL Files</glossterm> is renamed and reused.
+     </para>
+     <para>
+      The sequence of <glossterm>WAL Records</glossterm> in combination with
+      the sequence of <glossterm>WAL Files</glossterm> represents the
+      sequence of changes that have taken place in the
+      <glossterm>Cluster</glossterm>.
+     </para>
+      <para>
+       For more information, see
+       <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+    <glossentry id="glossary-wal-log">
+    <glossterm>WAL Log</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-record">
+    <glossterm>WAL Record</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>WAL Record</glossterm> contains either new or changed
+      <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> data or
+      information about a <command>COMMIT</command>,
+      <command>ROLLBACK</command>, <command>SAVEPOINT</command>, or
+      <glossterm>Checkpointer</glossterm> operation. WAL records use a
+      non-printabe binary format.
+     </para>
+      <para>
+       For more information, see
+       <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-segment">
+    <glossterm>WAL Segment</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-segment-file">
+    <glossterm>WAL Segment File</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-writer">
+   <glossterm>WAL Writer</glossterm>
+   <glossdef>
+    <para>
+     This process writes <glossterm>WAL Records</glossterm> from
+     <glossterm>Shared Memory</glossterm> to <glossterm>WAL
+     Files</glossterm>.
+    </para>
+      <para>
+       For more information, see
+       <link linkend="runtime-config-wal">Server Configuration: Write Ahead Log</link>.
+     </para>
+   </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-window-function">
+    <glossterm>Window Function</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Function</glossterm> similar to an
+      <glossterm>Aggregate</glossterm> in that can derive its value from a
+      set of <glossterm>Rows</glossterm> in a <glossterm>Result
+      Set</glossterm>, but still retaining the original source data.
+     </para>
+     <para>
+      For more information, see
+      <link linkend="tutorial-window">Window Functions</link>.
+     </para>
+    </glossdef>
+   </glossentry>
+  </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index e59cba7997..2183e33bea 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
   &docguide;
   &limits;
   &acronyms;
+  &glossary;
 
  </part>
 
-- 
2.20.1

From ead11072a6f04ca5e3789b1095d2605d0e1abd29 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 19 Mar 2020 20:54:20 -0300
Subject: [PATCH 2/2] Change all "For more info, see X" links to <xref> style

avoids having to write down the title, which is not our style
---
 doc/src/sgml/glossary.sgml | 88 +++++++++++++++++++-------------------
 1 file changed, 44 insertions(+), 44 deletions(-)

diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index cf20fb759c..612ce6e5f4 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -20,7 +20,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="functions-aggregate">Aggregate Functions</link>.
+      <xref linkend="functions-aggregate"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -35,7 +35,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="tutorial-window">Window Functions</link>.
+      <xref linkend="tutorial-window"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -49,7 +49,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="continuous-archiving">Backup and Restore: Continuous Archiving and Point-in-Time Recovery (PITR)</link>.
+      <xref linkend="continuous-archiving"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -93,7 +93,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="routine-vacuuming">Routine Database Maintenance Tasks: Routine Vacuuming</link>.
+      <xref linkend="routine-vacuuming"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -133,7 +133,7 @@
     </para>
     <para>
      For more information, see
-     <link linkend="bgworker">Background Worker Processes</link>.
+     <xref linkend="bgworker"/>.
     </para>
     </glossdef>
    </glossentry>
@@ -150,7 +150,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="runtime-config-resource">Server Configuration: Resource Consumption</link>.
+      <xref linkend="runtime-config-resource"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -175,7 +175,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+      <xref linkend="manage-ag-overview"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -196,7 +196,7 @@
      </para>
     <para>
      For more information, see
-     <link linkend="ddl-constraints">Constraints</link>.
+     <xref linkend="ddl-constraints"/>.
     </para>
     </glossdef>
    </glossentry>
@@ -269,7 +269,7 @@
      </para>
     <para>
      For more information, see
-     <link linkend="sql-commit">SQL Commands: COMMIT</link>.
+     <xref linkend="sql-commit"/>.
     </para>
     </glossdef>
    </glossentry>
@@ -305,7 +305,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="ddl-constraints">Constraints</link>.
+      <xref linkend="ddl-constraints"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -332,7 +332,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+      <xref linkend="storage-file-layout"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -345,7 +345,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+      <xref linkend="manage-ag-overview"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -378,7 +378,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-delete">SQL Commands: DELETE</link>.
+      <xref linkend="sql-delete"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -393,7 +393,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="storage-file-layout">Database Physical Storage: Database File Layout</link>.
+      <xref linkend="storage-file-layout"/>.
      </para>
      <para>
       (Don't confuse this term with the similar term
@@ -414,7 +414,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createforeigndatawrapper">SQL Commands: CREATE FOREIGN DATA WRAPPER</link>.
+      <xref linkend="sql-createforeigndatawrapper"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -442,7 +442,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createserver">SQL Commands: CREATE SERVER</link>.
+      <xref linkend="sql-createserver"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -460,7 +460,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createforeigntable">SQL Commands: CREATE FOREIGN TABLE</link>.
+      <xref linkend="sql-createforeigntable"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -476,7 +476,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createfunction">SQL Commands: CREATE FUNCTION</link>.
+      <xref linkend="sql-createfunction"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -512,7 +512,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-grant">SQL Commands: GRANT</link>.
+      <xref linkend="sql-grant"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -550,7 +550,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createindex">SQL Commands: CREATE INDEX</link>.
+      <xref linkend="sql-createindex"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -564,7 +564,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-insert">SQL Commands: INSERT</link>.
+      <xref linkend="sql-insert"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -720,7 +720,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-creatematerializedview">SQL Commands: CREATE MATERIALIZED VIEW</link>.
+      <xref linkend="sql-creatematerializedview"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -769,7 +769,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="server-start">Server Setup and Operation: Starting the Database Server</link>
+      <xref linkend="server-start"/>
      </para>
     </glossdef>
    </glossentry>
@@ -806,7 +806,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createprocedure">SQL Commands: CREATE PROCEDURE</link>.
+      <xref linkend="sql-createprocedure"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -904,7 +904,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-revoke">SQL Commands: REVOKE</link>.
+      <xref linkend="sql-revoke"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -921,7 +921,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createrole">SQL Commands: CREATE ROLE</link>.
+      <xref linkend="sql-createrole"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -935,7 +935,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-rollback">SQL Commands: ROLLBACK</link>.
+      <xref linkend="sql-rollback"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -959,7 +959,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-savepoint">SQL Commands: SAVEPOINT</link>.
+      <xref linkend="sql-savepoint"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -1083,7 +1083,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createsequence">SQL Commands: CREATE SEQUENCE</link>.
+      <xref linkend="sql-createsequence"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -1107,7 +1107,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="runtime-config-resource-memory">Server Configuration: Resource Consumption</link>.
+      <xref linkend="runtime-config-resource-memory"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -1127,7 +1127,7 @@
      </para>
      <para>
        For more information, see
-       <link linkend="manage-ag-overview">Managing Databases: Overview</link>.
+       <xref linkend="manage-ag-overview"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -1141,7 +1141,7 @@
      </para>
      <para>
        For more information, see
-       <link linkend="monitoring-stats">Monitoring Database Activity: The Statistics Collector</link>.
+       <xref linkend="monitoring-stats"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -1162,7 +1162,7 @@
      </para>
      <para>
        For more information, see
-       <link linkend="ddl-schemas">Data Definition: Schemas</link>.
+       <xref linkend="ddl-schemas"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -1181,7 +1181,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>.
+      <xref linkend="sql-createtable"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -1200,7 +1200,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createtable">SQL Commands: CREATE TABLE</link>
+      <xref linkend="sql-createtable"/>
      </para>
     </glossdef>
    </glossentry>
@@ -1216,7 +1216,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="transaction-iso">Transaction Isolation</link>
+      <xref linkend="transaction-iso"/>
      </para>
     </glossdef>
    </glossentry>
@@ -1235,7 +1235,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createtrigger">SQL Commands: CREATE TRIGGER</link>
+      <xref linkend="sql-createtrigger"/>
      </para>
     </glossdef>
    </glossentry>
@@ -1288,7 +1288,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-update">SQL Commands: UPDATE</link>
+      <xref linkend="sql-update"/>
      </para>
     </glossdef>
    </glossentry>
@@ -1313,7 +1313,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createusermapping">SQL Commands: CREATE USER MAPPING</link>
+      <xref linkend="sql-createusermapping"/>
      </para>
     </glossdef>
    </glossentry>
@@ -1331,7 +1331,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="sql-createview">SQL Commands: CREATE VIEW</link>
+      <xref linkend="sql-createview"/>
      </para>
     </glossdef>
    </glossentry>
@@ -1357,7 +1357,7 @@
      </para>
       <para>
        For more information, see
-       <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+       <xref linkend="wal-internals"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -1384,7 +1384,7 @@
      </para>
       <para>
        For more information, see
-       <link linkend="wal-internals">Reliability and the Write-Ahead Log: WAL Internals</link>.
+       <xref linkend="wal-internals"/>.
      </para>
     </glossdef>
    </glossentry>
@@ -1417,7 +1417,7 @@
     </para>
       <para>
        For more information, see
-       <link linkend="runtime-config-wal">Server Configuration: Write Ahead Log</link>.
+       <xref linkend="runtime-config-wal"/>.
      </para>
    </glossdef>
    </glossentry>
@@ -1433,7 +1433,7 @@
      </para>
      <para>
       For more information, see
-      <link linkend="tutorial-window">Window Functions</link>.
+      <xref linkend="tutorial-window"/>.
      </para>
     </glossdef>
    </glossentry>
-- 
2.20.1

diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index 612ce6e5f4..05fca33d9b 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -6,25 +6,34 @@
   systems in general.
  </para>
   <glosslist>
-   <glossentry id="glossary-aggregate">
-    <glossterm>Aggregate</glossterm>
+   <glossentry id="glossary-aggregating">
+    <glossterm>Aggregating</glossterm>
     <glossdef>
      <para>
-      To combine a collection of data values into a single value, whose
-      value may not be of the same type as the original values.
-      <glossterm>Aggregate</glossterm> <glossterm>Functions</glossterm>
-      combine multiple <glossterm>Rows</glossterm> that share a common set
-      of values into one <glossterm>Row</glossterm>, which means that the
-      only data visible in the values in common, and the aggregates of the
-      non-common data.
+      The act of combining a collection of data (input) values into
+      a single output value, which may not be of the same type as the
+      input values.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-aggregate">
+    <glossterm>Aggregate Function</glossterm>
+    <glossdef>
+      A <glossterm>Function</glossterm> that combines multiple input values,
+      for example by counting, averaging or adding them all together,
+      yielding a single output value.
      </para>
      <para>
       For more information, see
       <xref linkend="functions-aggregate"/>.
      </para>
+     <para>
+      See also <glossterm>Window Function</glossterm>.
     </glossdef>
    </glossentry>
 
+<!-- 
    <glossentry id="glossary-analytic">
     <glossterm>Analytic</glossterm>
     <glossdef>
@@ -39,13 +48,15 @@
      </para>
     </glossdef>
    </glossentry>
+-->
 
    <glossentry id="glossary-archiver">
     <glossterm>Archiver</glossterm>
     <glossdef>
      <para>
-      A process that backs up <glossterm>WAL Files</glossterm> in order to
-      reclaim space on the file system.
+      A process that saves aside copies of <glossterm>WAL Files</glossterm>,
+      for the purposes of creating backup copies or keeping
+      <glossterm>Replicas</glossterm> current.
      </para>
      <para>
       For more information, see
@@ -59,16 +70,15 @@
     <glossdef>
      <para>
       In reference to the value of an <glossterm>Attribute</glossterm> or
-      <glossterm>Datum</glossterm>: cannot be broken down into smaller
-      components.
+      <glossterm>Datum</glossterm>: the property that it cannot be broken down
+      into smaller components.
      </para>
      <para>
       In reference to an operation: An event that cannot be completed in
       part: it must either entirely succeed or entirely fail. A series of
       <acronym>SQL</acronym> statements can be combined into a
       <glossterm>Transaction</glossterm>, and that
-      <glossterm>transaction</glossterm> is said to be
-      <glossterm>Atomic</glossterm>.
+      transaction is said to be atomic.
      </para>
     </glossdef>
    </glossentry>
@@ -112,6 +122,7 @@
     </glossdef>
    </glossentry>
 
+<!--
    <glossentry id="glossary-backend-server">
     <glossterm>Backend Server</glossterm>
     <glossdef>
@@ -120,6 +131,7 @@
      </para>
     </glossdef>
    </glossentry>
+-->
 
    <glossentry id="glossary-background-worker">
     <glossterm>Background Worker</glossterm>
@@ -142,8 +154,9 @@
     <glossterm>Background Writer</glossterm>
     <glossdef>
      <para>
-      Writes continuously dirty pages from <glossterm>Shared
-      Memory</glossterm> to the file system. It starts periodically, but
+      A process that continuously writes dirty pages from
+      <glossterm>Shared Memory</glossterm> to the file system.
+      It starts periodically, but
       works only for a short period in order to distribute expensive
       <acronym>I/O</acronym> activity over time instead of generating fewer
       large <acronym>I/O</acronym> peaks which could block other processes.
@@ -218,10 +231,9 @@
     <glossterm>Checkpoint</glossterm>
     <glossdef>
      <para>
-      A <link linkend="sql-checkpoint"> Checkpoint</link> is a point in time
-      when all older dirty pages of the <glossterm>Shared
-      Memory</glossterm>, all older <glossterm>WAL records</glossterm>, and
-      a special <glossterm>Checkpoint record</glossterm> have been written
+      A point in time when all older dirty pages of the
+      <glossterm>Shared Memory</glossterm>, all older <glossterm>WAL records</glossterm>,
+      and a special <glossterm>Checkpoint record</glossterm> have been written
       and flushed to disk.
      </para>
     </glossdef>
@@ -543,8 +555,8 @@
     <glossdef>
      <para>
       A <glossterm>Relation</glossterm> that contains data derived from a
-      <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> such
-      as a <glossterm>Materialized View</glossterm>). It's internal
+      <glossterm>Table</glossterm> (or other kind of <glossterm>Relation</glossterm>
+      such as a <glossterm>Materialized View</glossterm>). Its internal
       structure supports very fast retrieval of and access to the original
       data.
      </para>
@@ -815,7 +827,7 @@
     <glossterm>Record</glossterm>
     <glossdef>
      <para>
-      See <link linkend="sql-revoke">Tupple</link>.
+      See <glossterm>Tuple</glossterm>.
      </para>
      <para>
       A single <glossterm>Row</glossterm> of a <glossterm>Table</glossterm>
@@ -944,7 +956,7 @@
     <glossterm>Row</glossterm>
     <glossdef>
      <para>
-      See <link linkend="sql-revoke">Tupple</link>.
+      See <glossterm>Tuple</glossterm>.
      </para>
     </glossdef>
    </glossentry>
@@ -1194,9 +1206,9 @@
       <glossterm>Session</glossterm> or a
       <glossterm>Transaction</glossterm>, as defined at creation time. The
       data in them is not visible to other <glossterm>Sessions</glossterm>,
-      and is not <glossterm>Logged</glossterm>. <glossterm>Temporary
-      Tables</glossterm> are most often used to store intermediate data for
-      a multi-step data transformation.
+      and is not <glossterm>Logged</glossterm>.
+      <glossterm>Temporary Tables</glossterm> are often used to store
+      intermediate data for a multi-step data transformation.
      </para>
      <para>
       For more information, see
@@ -1227,8 +1239,9 @@
      <para>
       A <glossterm>Function</glossterm> which can be defined to execute
       whenever a certain operation (<command>INSERT</command>,
-      <command>UPDATE</command>, or <command>DELTE</command>) is applied to
-      that <glossterm>Relation</glossterm>. A <glossterm>Trigger</glossterm>
+      <command>UPDATE</command>, <command>DELETE</command>,
+      <command>TRUNCATE</command>) is applied to a <glossterm>Relation</glossterm>.
+      A <glossterm>Trigger</glossterm>
       executes within the same <glossterm>Transaction</glossterm> as the
       statement which invoked it, and if the <glossterm>Function</glossterm>
       fails then the invoking statement also fails.
@@ -1249,8 +1262,8 @@
       the <glossterm>Tuple</glossterm> is found, in which case the
       <glossterm>Tuple</glossterm> is often called a
       <glossterm>Row</glossterm> or <glossterm>Record</glossterm>. It may
-      also be defined by the structure of a <glossterm>Result
-      Set</glossterm>.
+      also be defined by the structure of a
+      <glossterm>Result Set</glossterm>.
      </para>
     </glossdef>
    </glossentry>
@@ -1260,7 +1273,7 @@
     <glossdef>
      <para>
       The condition of having no matching values in the same
-      <glossterm>Relation</glossterm>. Most often used in the concept of
+      <glossterm>Relation</glossterm>. Often used in the concept of
       <glossterm>Unique Indexes</glossterm>.
      </para>
     </glossdef>

From 8a163603102f51a3eddfb05c51baf3b840c5d7f7 Mon Sep 17 00:00:00 2001
From: coreyhuinker <corey.huinker@gmail.com>
Date: Mon, 30 Mar 2020 13:08:27 -0400
Subject: [PATCH] glossary v4

---
 doc/src/sgml/filelist.sgml |    1 +
 doc/src/sgml/glossary.sgml | 1551 ++++++++++++++++++++++++++++++++++++
 doc/src/sgml/postgres.sgml |    1 +
 3 files changed, 1553 insertions(+)
 create mode 100644 doc/src/sgml/glossary.sgml

diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 1043d0f7ab..cf21ef857e 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..eab14f3c9b
--- /dev/null
+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,1551 @@
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+  This is a list of terms and their meaning in the context of
+  <productname>PostgreSQL</productname> and relational database
+  systems in general.
+ </para>
+  <glosslist>
+   <glossentry id="glossary-aggregating">
+    <glossterm>Aggregating</glossterm>
+    <glossdef>
+     <para>
+      The act of combining a collection of data (input) values into
+      a single output value, which may not be of the same type as the
+      input values.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-aggregate">
+    <glossterm>Aggregate Function</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Function</glossterm> that combines multiple input values,
+      for example by counting, averaging or adding them all together,
+      yielding a single output value.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="functions-aggregate"/>.
+     </para>
+     <para>
+      See also <glossterm>Window Function</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-analytic">
+    <glossterm>Analytic</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Function</glossterm> whose computed value can reference
+      values found in nearby <glossterm>Row</glossterm>s of the same
+      <glossterm>Result Set</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="tutorial-window"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-atomic">
+    <glossterm>Atomic</glossterm>
+    <glossdef>
+     <para>
+      In reference to the value of an <glossterm>Attribute</glossterm> or
+      <glossterm>Datum</glossterm>: an item that cannot be broken down
+      into smaller components.
+     </para>
+     <para>
+      In reference to an operation: an event that cannot be completed in
+      part; it must either entirely succeed or entirely fail. For
+      example, a series of <acronym>SQL</acronym> statements can be
+      combined into a <glossterm>Transaction</glossterm>, and that
+      transaction is said to be atomic.
+      <glossterm>Atomic</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-atomicity">
+    <glossterm>Atomicity</glossterm>
+    <glossdef>
+     <para>
+      One of the <acronym>ACID</acronym> properties. This is the state of 
+      being <glossterm>Atomic</glossterm> in the operational/transactional sense.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-attribute">
+    <glossterm>Attribute</glossterm>
+    <glossdef>
+     <para>
+      An element with a certain name and data type found within a
+      <glossterm>Tuple</glossterm> or <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-autovacuum">
+    <glossterm>Autovacuum</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>Background Worker</glossterm> processes that routinely
+      perform <glossterm>Vacuum</glossterm> operations.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="routine-vacuuming"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-backend-process">
+    <glossterm>Backend Process</glossterm>
+    <glossdef>
+     <para>
+      Processes of an <glossterm>Instance</glossterm> which act on behalf of
+      client <glossterm>Connection</glossterm>s and handle their requests.
+     </para>
+     <para>
+      (Don't confuse this term with the similar terms <glossterm>Background
+      Worker</glossterm> or <glossterm>Background Writer</glossterm>).
+     </para>
+    </glossdef>
+   </glossentry>
+
+<!--
+   <glossentry id="glossary-backend-server">
+    <glossterm>Backend Server</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Instance</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+-->
+
+   <glossentry id="glossary-background-worker">
+    <glossterm>Background Worker</glossterm>
+    <glossdef>
+     <para>
+      Individual processes within an <glossterm>Instance</glossterm>, which
+      run system- or user-supplied code. A typical use case is a process
+      which handles parts of an <acronym>SQL</acronym> query to take
+      advantage of parallel execution on servers with multiple
+      <acronym>CPU</acronym>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="bgworker"/>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-background-writer">
+    <glossterm>Background Writer</glossterm>
+    <glossdef>
+     <para>
+      A process that continuously writes dirty pages from
+      <glossterm>Shared Memory</glossterm> to the file system.
+      It wakes up periodically, but
+      works only for a short period in order to distribute expensive
+      <acronym>I/O</acronym> activity over time, instead of generating fewer
+      larger <acronym>I/O</acronym> peaks which could block other processes.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="runtime-config-resource"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-cast">
+    <glossterm>Cast</glossterm>
+    <glossdef>
+     <para>
+      A conversion of a <glossterm>Datum</glossterm> from its current data
+      type to another data type.
+     </para>
+    </glossdef>
+   </glossentry>
+
+ <glossentry id="glossary-catalog">
+    <glossterm>Catalog</glossterm>
+    <glossdef>
+     <para>
+      The <acronym>SQL</acronym> standard uses this term to
+      indicate what is called a <glossterm>Database</glossterm> in
+      <productname>PostgreSQL</productname>'s terminology.
+     </para>
+     <para>
+      This should not be confused with the
+      <glossterm>System Catalog</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="manage-ag-overview"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-check-constraint">
+    <glossterm>Check Constraint</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Constraint</glossterm> defined on a
+      <glossterm>Relation</glossterm> which restricts the values allowed in
+      one or more <glossterm>Attribute</glossterm>s. The <glossterm>Check
+      Constraint</glossterm> can make reference to any
+      attribute in the
+      <glossterm>Relation</glossterm>, but cannot reference other
+      <glossterm>Row</glossterm>s of the same
+      relation or other relations.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="ddl-constraints"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-checkpointer">
+    <glossterm>Checkpointer</glossterm>
+    <glossdef>
+     <para>
+      A process that writes dirty pages and <glossterm>WAL
+      Record</glossterm>s to the file system and creates a special
+      checkpoint record. This process is initiated when predefined
+      conditions are met, such as a specified amount of time has passed, or
+      a certain volume of records have been collected.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-checkpoint">
+    <glossterm>Checkpoint</glossterm>
+    <glossdef>
+     <para>
+      A point in time when all older dirty pages of the
+      <glossterm>Shared Memory</glossterm>, all older <glossterm>WAL Record</glossterm>s,
+      and a special <glossterm>Checkpoint record</glossterm> have been written
+      and flushed to disk.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-checkpoint"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-cluster">
+    <glossterm>Cluster</glossterm>
+    <glossdef>
+     <para>
+      A group of <glossterm>Database</glossterm>s plus their
+      <glossterm>Global SQL Object</glossterm>s. The
+      <glossterm>Cluster</glossterm> is managed by exactly one
+      <glossterm>Instance</glossterm>. A newly created
+      <glossterm>Cluster</glossterm> will have three
+      <glossterm>Database</glossterm>s created automatically. They are
+      <literal>template0</literal>, <literal>template1</literal>, and
+      <literal>postgres</literal>. It is expected that an application will
+      create one or more additional <glossterm>Database</glossterm>s aside
+      from these three.
+     </para>
+     <para>
+      Don't confuse the <productname>PostgreSQL</productname>-specific term
+      <glossterm>Cluster</glossterm> with the SQL command
+      <literal>CLUSTER</literal>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-column">
+    <glossterm>Column</glossterm>
+    <glossdef>
+     <para>
+      An <glossterm>Attribute</glossterm> found in a
+      <glossterm>Table</glossterm> or <glossterm>View</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-commit">
+    <glossterm>Commit</glossterm>
+    <glossdef>
+     <para>
+      The act of finalizing a <glossterm>Transaction</glossterm> within the
+      <glossterm>Database</glossterm>.
+     </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-commit"/>.
+    </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-concurrency">
+    <glossterm>Concurrency</glossterm>
+    <glossdef>
+     <para>
+      The concept that multiple independent operations happen within the
+      <glossterm>Database</glossterm> at the same time.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-connection">
+    <glossterm>Connection</glossterm>
+    <glossdef>
+     <para>
+      An established line of communication between a client process
+      and a server process. If the two involved processes reside on the
+      same <glossterm>Server</glossterm>, then the connection can either use
+      <acronym>TCP/IP</acronym> or Unix-domain sockets. Otherwise,
+      only <acronym>TCP/IP</acronym> can be used.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="runtime-config-connection"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-consistency">
+    <glossterm>Consistency</glossterm>
+    <glossdef>
+     <para>
+      One of the <acronym>ACID</acronym> properties. This means that the database
+      is always in compliance with its own rules such as <glossterm>Table</glossterm>
+      structure, <glossterm>Constraint</glossterm>s,
+      <glossterm>Uniqueness</glossterm>, etc.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-constraint">
+    <glossterm>Constraint</glossterm>
+    <glossdef>
+     <para>
+      A restriction on the values of data allowed within a
+      <glossterm>Table</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="ddl-constraints"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-data-area">
+    <glossterm>Data Area</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Data Directory</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-data-directory">
+    <glossterm>Data Directory</glossterm>
+    <glossdef>
+     <para>
+      The base directory on the filesystem of a
+      <glossterm>Server</glossterm> that contains all data files and
+      subdirectories associated with a <glossterm>Cluster</glossterm> with
+      the exception of <glossterm>Tablespace</glossterm>s. The environment
+      variable <literal>PGDATA</literal> often &mdash; but not always &mdash;
+      refers to the <glossterm>Data Directory</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="storage-file-layout"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-database">
+    <glossterm>Database</glossterm>
+    <glossdef>
+     <para>
+      A named collection of <glossterm>SQL Object</glossterm>s.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="manage-ag-overview"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-database-server">
+    <glossterm>Database Server</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Instance</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-datum">
+    <glossterm>Datum</glossterm>
+    <glossdef>
+     <para>
+      The internal representation of a <acronym>SQL</acronym> data type.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-delete">
+    <glossterm>Delete</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command which removes
+      <glossterm>Row</glossterm>s from a given <glossterm>Table</glossterm>
+      or <glossterm>Relation</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-delete"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-durability">
+    <glossterm>Durability</glossterm>
+    <glossdef>
+     <para>
+      One of the <acronym>ACID</acronym> properties. This is the assurance that once a
+      <glossterm>Transaction</glossterm> has been <glossterm>Committed</glossterm>, the
+      data will remain even after a system failure or crash.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-file-segment">
+    <glossterm>File Segment</glossterm>
+    <glossdef>
+     <para>
+       A physical file which stores data for a given
+       <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> object.
+       <glossterm>File Segment</glossterm>s are limited in size by a
+       configuration value and if that size is exceeded, it will be split
+       into multiple physical files.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="storage-file-layout"/>.
+     </para>
+     <para>
+      (Don't confuse this term with the similar term
+      <glossterm>WAL Segment</glossterm>).
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-data-wrapper">
+    <glossterm>Foreign Data Wrapper</glossterm>
+    <glossdef>
+     <para>
+      A means of representing data that is not contained in the local
+      <glossterm>Database</glossterm> so that it appears as if were in local
+      <glossterm>Table</glossterm>(s). With a Foreign Data Wrapper it is
+      possible to define a <glossterm>Foreign Server</glossterm> and
+      <glossterm>Foreign Table</glossterm>s.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createforeigndatawrapper"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-key">
+    <glossterm>Foreign Key</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Constraint</glossterm> defined on one or more
+      <glossterm>Column</glossterm>s in a <glossterm>Table</glossterm> which
+      requires the value(s) in those <glossterm>Column</glossterm>s to
+      identify exactly one <glossterm>Row</glossterm> in the specified
+      <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-server">
+    <glossterm>Foreign Server</glossterm>
+    <glossdef>
+     <para>
+      A named collection of <glossterm>Foreign Table</glossterm>s which all
+      use the same <glossterm>Foreign Data Wrapper</glossterm> and have
+      other configuration values in common.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createserver"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-foreign-table">
+    <glossterm>Foreign Table</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> which appears to have
+      <glossterm>Row</glossterm>s and <glossterm>Column</glossterm>s similar
+      to a regular <glossterm>Table</glossterm>, but will forward requests
+      for data through its <glossterm>Foreign Data Wrapper</glossterm>,
+      which will return <glossterm>Result Set</glossterm>s structured
+      according to the definition of the <glossterm>Foreign Table</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createforeigntable"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-function">
+    <glossterm>Function</glossterm>
+    <glossdef>
+     <para>
+      Any defined transformation of data. Many
+      <glossterm>Function</glossterm>s are already defined within
+      <productname>PostgreSQL</productname> itself, but user-defined
+      ones can also be added.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createfunction"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-global-sql-object">
+    <glossterm>Global SQL Object</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>SQL Object</glossterm>s which do not belong to a specific
+      <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+      Objects that exist at the <glossterm>Database</glossterm> level
+      include Extensions such as
+      <glossterm>Foreign Data Wrapper</glossterm>s.
+     </para>
+     <para>
+      Objects that exist at the <glossterm>Cluster</glossterm> level
+      include <glossterm>Role</glossterm>s,
+      <glossterm>Tablespace</glossterm>s,
+      <glossterm>Replication</glossterm> origins, and subscriptions
+      for logical replication.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-grant">
+    <glossterm>Grant</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command that is used to allow
+      <glossterm>User</glossterm>s or <glossterm>Role</glossterm>s to access
+      specific objects within the <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-grant"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-heap">
+    <glossterm>Heap</glossterm>
+    <glossdef>
+     <para>
+      Contains the values of <glossterm>Row</glossterm> attributes
+      (i.e. the data). The <glossterm>Heap</glossterm> is realized within
+      <glossterm>Database</glossterm> files.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-host">
+    <glossterm>Host</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Server</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-index">
+    <glossterm>Index</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that contains data derived from a
+      <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> types
+      such as a <glossterm>Materialized View</glossterm>). Its internal
+      structure supports fast retrieval of and access to the original
+      data.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createindex"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-insert">
+    <glossterm>Insert</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> command used to add new data into a
+      <glossterm>Table</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-insert"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-instance">
+    <glossterm>Instance</glossterm>
+    <glossdef>
+     <para>
+      An <glossterm>Instance</glossterm> is a group of processes plus their
+      common <glossterm>Shared Memory</glossterm> running on a single
+      <glossterm>Server</glossterm>. The <glossterm>Instance</glossterm>
+      handles all key features of a <acronym>DBMS</acronym>: read and write
+      access to files and shared memory, assurance of
+      the <acronym>ACID</acronym> paradigm, <acronym>MVCC</acronym>,
+      <glossterm>Connection</glossterm>s to client programs, backup,
+      recovery, replication, privileges, etc.
+     </para>
+     <para>
+      An <glossterm>Instance</glossterm> manages exactly one
+      <glossterm>Cluster</glossterm>.
+     </para>
+     <para>
+      Many <glossterm>Instance</glossterm>s can run on the same server as
+      long as their <acronym>TCP/IP</acronym> ports do not conflict.
+      Different instances on a server may use the
+      same or different versions of <productname>PostgreSQL</productname>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-isolation">
+    <glossterm>Isolation</glossterm>
+    <glossdef>
+     <para>
+      One of the <acronym>ACID</acronym> properties. This means that concurrently running 
+      <glossterm>Transaction</glossterm>s affect the database exactly as if they had been
+      executed sequentially.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-join">
+    <glossterm>Join</glossterm>
+    <glossdef>
+     <para>
+      A <acronym>SQL</acronym> keyword used in <command>SELECT</command> statements for
+      combining data from multiple <glossterm>Relation</glossterm>s.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-key">
+    <glossterm>Key</glossterm>
+    <glossdef>
+     <para>
+      A means of identifying a <glossterm>Row</glossterm> within a
+      <glossterm>Table</glossterm> or <glossterm>Relation</glossterm> by
+      values contained within one or more <glossterm>Attribute</glossterm>s
+      in that <glossterm>Table</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-lock">
+    <glossterm>Lock</glossterm>
+    <glossdef>
+     <para>
+      A mechanism that allows a process to limit or prevent simultaneous
+      access to a resource.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-file">
+    <glossterm>Log File</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>Log File</glossterm>s contain human-readable text lines about
+      events. Examples include login failures, long-running queries, etc.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="logfile-maintenance"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-writer">
+    <glossterm>Log Writer</glossterm>
+    <glossdef>
+     <para>
+      If activated and parameterized, the
+      <glossterm>Log Writer</glossterm> process
+      writes information about database events into the current
+      <glossterm>Log File</glossterm>. When reaching certain time- or
+      volume-dependent criteria, a new log file is created.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="runtime-config-logging"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-log-record">
+    <glossterm>Log Record</glossterm>
+     <glossdef>
+      <para>
+       Archaic term for a <glossterm>WAL Record</glossterm>.
+      </para>
+     </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-logged">
+    <glossterm>Logged</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Table</glossterm> is considered
+      <glossterm>Logged</glossterm> if changes to it are sent to the
+      <glossterm>WAL Log</glossterm>. By default, all regular
+      <glossterm>Table</glossterm>s are <glossterm>Logged</glossterm>. A
+      table can be specified as <glossterm>Unlogged</glossterm> either at
+      creation time or via the <command>ALTER TABLE</command> command.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-master">
+    <glossterm>Master</glossterm>
+    <glossdef>
+     <para>
+      When two or more <glossterm>Database</glossterm>s are linked via
+      <glossterm>Replication</glossterm>, the <glossterm>Server</glossterm>
+      that is considered the authoritative source of information is called
+      the <glossterm>Master</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-materialized">
+    <glossterm>Materialized</glossterm>
+    <glossdef>
+     <para>
+      The act of storing information rather than just the method of accessing
+      the information. This term is used in <glossterm>Materialized
+      View</glossterm>s, meaning that the data derived from the
+      <glossterm>View</glossterm> is actually stored on disk separately from
+      the sources of that data. When using the term
+      <glossterm>Materialized</glossterm> to refer to
+      multi-step queries, it means that the data of a given step is stored
+      in memory, but that storage may spill over onto disk.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-materialized-view">
+    <glossterm>Materialized View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that is defined in the same way that
+      a <glossterm>View</glossterm> is, but stores data in the same way
+      that a <glossterm>Table</glossterm> does. It cannot be modified via
+      <command>INSERT</command>, <command>UPDATE</command>, or
+      <command>DELETE</command> operations.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-creatematerializedview"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-null">
+    <glossterm>Null</glossterm>
+    <glossdef>
+     <para>
+      A concept of non-existence that is a central tenet of Relational
+      Database Theory. It represents the absence of value.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-partition">
+    <glossterm>Partition</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Table</glossterm> that can be queried directly,
+      or via a partitioned table, which is a collection of
+      sub-tables, each capable of holding one defined
+      subset of information that does not overlap with any other
+      table in the collection.
+     </para>
+     <para>
+      When referring to an <glossterm>Analytic</glossterm>
+      <glossterm>Function</glossterm>: a partition is a definition
+      that identifies which neighboring
+      <glossterm>Row</glossterm>s can be considered by the
+      function.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-postmaster">
+    <glossterm>Postmaster</glossterm>
+    <glossdef>
+     <para>
+       The very first process of an <glossterm>Instance</glossterm>. It
+       starts the other processes and creates
+       <glossterm>Backend Process</glossterm>es on demand.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="server-start"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-primary-key">
+    <glossterm>Primary Key</glossterm>
+    <glossdef>
+     <para>
+      A special case of a <glossterm>Unique Index</glossterm> defined on a
+      <glossterm>Table</glossterm> or other <glossterm>Relation</glossterm>
+      that also guarantees that all of the <glossterm>Attribute</glossterm>s
+      within the <glossterm>Primary Key</glossterm> do not have
+      <glossterm>Null</glossterm> values.  As the name implies, there can be
+      only one <glossterm>Primary Key</glossterm> per
+      table, though it is possible to have multiple
+      unique indexes that also have no null-capable attributes.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-procedure">
+    <glossterm>Procedure</glossterm>
+    <glossdef>
+     <para>
+      A defined set of instructions for manipulating data within a
+      <glossterm>Database</glossterm>. A <glossterm>Procedure</glossterm> can
+      be written in a variety of programming languages. They may seem
+      similar to <glossterm>Function</glossterm>s, but are different in that
+      they must be invoked via the <command>CALL</command> command rather
+      than the <command>SELECT</command> or <command>PERFORM</command>
+      commands, and they are allowed to make transactional statements such
+      as <command>COMMIT</command> and <command>ROLLBACK</command>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createprocedure"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-record">
+    <glossterm>Record</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Tuple</glossterm>.
+     </para>
+     <para>
+      A single <glossterm>Row</glossterm> of a <glossterm>Table</glossterm>
+      or other <glossterm>Relation</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-referential-integrity">
+    <glossterm>Referential Integrity</glossterm>
+    <glossdef>
+     <para>
+      A means of restricting data in one <glossterm>Relation</glossterm>
+      so that it must have matching data in another
+      <glossterm>Relation</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-relation">
+    <glossterm>Relation</glossterm>
+    <glossdef>
+     <para>
+      The generic term for all objects in a <glossterm>Database</glossterm>
+      that have a name and a list of <glossterm>Attribute</glossterm>s
+      defined in a specific order. <glossterm>Table</glossterm>s,
+      <glossterm>View</glossterm>s, <glossterm>Foreign Table</glossterm>s,
+      <glossterm>Materialized View</glossterm>s, and
+      <glossterm>Index</glossterm>es are all
+      <glossterm>Relation</glossterm>s.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-replica">
+    <glossterm>Replica</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Database</glossterm> that is paired with a 
+      <glossterm>Master</glossterm>
+      database and is maintaining a copy of some or
+      all of the Master <glossterm>Database</glossterm>'s data. The primary
+      reasons for doing this are to allow for greater access to that data,
+      and to maintain availability of the data in the event that the
+      <glossterm>Master</glossterm> becomes unavailable.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-replication">
+    <glossterm>Replication</glossterm>
+    <glossdef>
+     <para>
+       The act of reproducing data on one <glossterm>Server</glossterm> onto
+       another server called a <glossterm>Replica</glossterm>. This can take the
+       form of Physical <glossterm>Replication</glossterm>, where all file
+       changes from one server are copied verbatim,
+       or Logical <glossterm>Replication</glossterm> where a defined subset
+       of data changes are conveyed.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-result-set">
+    <glossterm>Result Set</glossterm>
+    <glossdef>
+     <para>
+      A data structure transmitted from a <glossterm>Server</glossterm> to
+      client program upon the completion of a <acronym>SQL</acronym>
+      command, usually a <command>SELECT</command> but it can be an
+      <command>INSERT</command>, <command>UPDATE</command>, or
+      <command>DELETE</command> command if the <literal>RETURNING</literal>
+      clause is specified. The data structure consists of zero or more
+      <glossterm>Row</glossterm>s with the same ordered set of
+      <glossterm>Attribute</glossterm>s.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-revoke">
+    <glossterm>Revoke</glossterm>
+    <glossdef>
+     <para>
+      A command to prevent access to a named set of
+      <glossterm>Database</glossterm> objects for a named list of
+      <glossterm>User</glossterm>s and <glossterm>Role</glossterm>s.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-revoke"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-role">
+    <glossterm>Role</glossterm>
+    <glossdef>
+     <para>
+      A collection of access privileges to the
+      <glossterm>Database</glossterm>. <glossterm>Role</glossterm>s are
+      themselves a privilege that can be granted to other roles. This is
+      often done for convenience or to ensure completeness when multiple
+      <glossterm>User</glossterm>s need the same privileges.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createrole"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-rollback">
+    <glossterm>Rollback</glossterm>
+    <glossdef>
+     <para>
+      A command to undo all of the operations performed since the beginning
+      of a <glossterm>Transaction</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-rollback"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-row">
+    <glossterm>Row</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>Tuple</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-savepoint">
+    <glossterm>Savepoint</glossterm>
+    <glossdef>
+     <para>
+      A special mark inside the sequence of steps in a
+      <glossterm>Transaction</glossterm>. Data modifications after this
+      point in time may be reverted to the time of the savepoint.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-savepoint"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-schema">
+    <glossterm>Schema</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Schema</glossterm> is a namespace for
+      <glossterm>SQL object</glossterm>s, which all reside in the same
+      <glossterm>database</glossterm>.  Each <glossterm>SQL
+      object</glossterm> must reside in exactly one
+      <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+      In general, the names of <glossterm>SQL Object</glossterm>s in the
+      schema are unique &mdash; even across different types of objects.  The lone
+      exception is the case of <glossterm>Unique</glossterm>
+      <glossterm>Constraint</glossterm>s, in which case there
+      <emphasis>must</emphasis> be a <glossterm>Unique Index</glossterm>
+      with the same name and <glossterm>Schema</glossterm> as the
+      <glossterm>Constraint</glossterm>.  There is no restriction on reusing
+      a name in multiple <glossterm>Schema</glossterm>s.
+     </para>
+     <para>
+      Many <glossterm>SQL Object</glossterm>s reside in the default
+      <glossterm>Schema</glossterm> <literal>public</literal>, but it is
+      expected that more schemas are created to hold application-specific
+      <glossterm>SQL Object</glossterm>s.
+     </para>
+     <para>
+      More generically, the term <glossterm>Schema</glossterm> is used to
+      mean all data descriptions (<glossterm>Table</glossterm> definitions,
+      <glossterm>Constraint</glossterm>s, comments) for a given
+      <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="ddl-schemas"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-segment">
+    <glossterm>Segment</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>File Segment</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-select">
+    <glossterm>Select</glossterm>
+    <glossdef>
+     <para>
+      The command used to query a <glossterm>Database</glossterm>. Normally,
+      <command>SELECT</command>s are not expected to modify the
+      <glossterm>Database</glossterm> in any way, but it is possible that
+      <glossterm>Function</glossterm>s invoked within the query could have
+      side effects that do modify data.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-select"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-serializable">
+    <glossterm>Serializable</glossterm>
+    <glossdef>
+     <para>
+      Transactions defined as <literal>SERIALIZABLE</literal> are unable to
+      see changes made within other transactions. In effect, for the
+      initializing session the entire <glossterm>Database</glossterm>
+      appears to be frozen for the duration of the
+      <glossterm>Transaction</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-server">
+    <glossterm>Server</glossterm>
+    <glossdef>
+     <para>
+      The term <glossterm>Server</glossterm> denotes real hardware, a
+      container, or a Virtual Machine.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-session">
+    <glossterm>Session</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Connection</glossterm> to the <glossterm>Database</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-sequence">
+    <glossterm>Sequence</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Database</glossterm> object which represents the
+      mathematical concept of a numerical integral sequence. It can be
+      thought of as a <glossterm>Table</glossterm> with exactly one
+      <glossterm>Row</glossterm> and one <glossterm>Column</glossterm>. The
+      value stored is known as the current value. A
+      <glossterm>Sequence</glossterm> has a defined direction (usually
+      increasing) and an interval step (usually 1).  Whenever the
+      <literal>NEXTVAL</literal> pseudo-column of a
+      <glossterm>Sequence</glossterm> is accessed, the current value is moved
+      in the defined direction by the defined interval step, that value
+      is returned to the invoking query, and the current value of the
+      sequence is updated to reflect the new value. The value can be updated
+      multiple times in a single query, the net effect being that each row
+      selected will have a different value. Values taken from a
+      <glossterm>Sequence</glossterm> are never reverted, even in the case of
+      a <glossterm>Rollback</glossterm>, which means that the
+      <glossterm>Sequence</glossterm> will never generate the same number twice,
+      which makes it useful for generating
+      <glossterm>Primary Key</glossterm> values.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createsequence"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-shared-memory">
+    <glossterm>Shared Memory</glossterm>
+    <glossdef>
+     <para>
+      <acronym>RAM</acronym> which is used by the processes common to an
+      <glossterm>Instance</glossterm>. It mirrors parts of
+      <glossterm>Database</glossterm> files, provides an area for
+      <glossterm>WAL Record</glossterm>s, and stores additional common
+      information. Note that <glossterm>Shared Memory</glossterm> belongs to
+      the complete <glossterm>Instance</glossterm>, not to a single
+      <glossterm>Database</glossterm>.
+     </para>
+     <para>
+      <glossterm>Shared Memory</glossterm> is organized into pages. If a
+      page is modified, it is called a dirty page until it is written back
+      to the file system.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="runtime-config-resource-memory"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-sql-object">
+    <glossterm>SQL Object</glossterm>
+     <glossdef>
+      <para>
+       A <glossterm>Table</glossterm>, <glossterm>View</glossterm>,
+       <glossterm>Materialized View</glossterm>,
+       <glossterm>Index</glossterm>, <glossterm>Constraint</glossterm>,
+       <glossterm>Sequence</glossterm>, <glossterm>Function</glossterm>,
+       <glossterm>Procedure</glossterm>, <glossterm>Trigger</glossterm>,
+       data type, or operator. Every <glossterm>SQL Object</glossterm>
+       belongs to exactly one <glossterm>Schema</glossterm>.
+     </para>
+     <para>
+       For more information, see
+       <xref linkend="manage-ag-overview"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-stats-collector">
+    <glossterm>Stats Collector</glossterm>
+    <glossdef>
+     <para>
+      This process collects statistical information about the
+      <glossterm>Cluster</glossterm>'s activities.
+     </para>
+     <para>
+       For more information, see
+       <xref linkend="monitoring-stats"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-system-catalog">
+    <glossterm>System Catalog</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Table</glossterm>s and
+      <glossterm>View</glossterm>s which describe the structure of all
+      <acronym>SQL</acronym> objects of the <glossterm>Database</glossterm>
+      and the <glossterm>Global SQL Object</glossterm>s of the
+      <glossterm>Cluster</glossterm>. The <glossterm>System
+      Catalog</glossterm> resides in the schema
+      <literal>pg_catalog</literal>. Main parts are mirrored as
+      <glossterm>View</glossterm>s in the <glossterm>Schema</glossterm>
+      <literal>information_schema</literal>.
+     </para>
+     <para>
+       For more information, see
+       <xref linkend="ddl-schemas"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-table">
+    <glossterm>Table</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Tuple</glossterm>s (also known as
+      <glossterm>Row</glossterm>s or <glossterm>Record</glossterm>s) having
+      a common data structure (the same number of
+      <glossterm>Attribute</glossterm>s, in the same order, having the same
+      name and type per position). A <glossterm>Table</glossterm> is the
+      most common form of <glossterm>Relation</glossterm> in
+      <productname>PostgreSQL</productname>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createtable"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-tablespace">
+    <glossterm>Tablespace</glossterm>
+    <glossdef>
+     <para>
+      A named location on the server filesystem. All <glossterm>SQL Object</glossterm>s
+      which require storage beyond their definition in the
+      <glossterm>System Catalog</glossterm>
+      must belong to a single tablespace.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="manage-ag-tablespaces"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-temporary-tables">
+    <glossterm>Temporary Table</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>Table</glossterm>s that exist either for the lifetime of a
+      <glossterm>Session</glossterm> or a
+      <glossterm>Transaction</glossterm>, as specified at the time of creation. The
+      data in them is not visible to other sessions,
+      and is not <glossterm>Logged</glossterm>.
+      <glossterm>Temporary Table</glossterm>s are often used to store
+      intermediate data for a multi-step operation.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createtable"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-transaction">
+    <glossterm>Transaction</glossterm>
+    <glossdef>
+     <para>
+      A combination of commands that must act as a single
+      <glossterm>Atomic</glossterm> command: they all succeed or all fail
+      as a single unit, and their effects are not visible to other
+      <glossterm>Session</glossterm>s until
+      the <glossterm>Transaction</glossterm> is complete.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="transaction-iso"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-trigger">
+    <glossterm>Trigger</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Function</glossterm> which can be defined to execute
+      whenever a certain operation (<command>INSERT</command>,
+      <command>UPDATE</command>, <command>DELETE</command>,
+      <command>TRUNCATE</command>) is applied to a <glossterm>Relation</glossterm>.
+      A <glossterm>Trigger</glossterm>
+      executes within the same <glossterm>Transaction</glossterm> as the
+      statement which invoked it, and if the <glossterm>Function</glossterm>
+      fails, then the invoking statement also fails.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createtrigger"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-tuple">
+    <glossterm>Tuple</glossterm>
+    <glossdef>
+     <para>
+      A collection of <glossterm>Attribute</glossterm>s in a fixed order.
+      That order may be defined by the <glossterm>Table</glossterm> where
+      the <glossterm>Tuple</glossterm> is found, in which case the
+      <glossterm>Tuple</glossterm> is often called a
+      <glossterm>Row</glossterm> or <glossterm>Record</glossterm>. It may
+      also be defined by the structure of a
+      <glossterm>Result Set</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-unique">
+    <glossterm>Unique</glossterm>
+    <glossdef>
+     <para>
+      The condition of having no duplicate values in the same
+      <glossterm>Relation</glossterm>. Often used in the concept of
+      <glossterm>Unique Index</glossterm>es.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-unlogged">
+    <glossterm>Unlogged</glossterm>
+    <glossdef>
+     <para>
+      Changes to an unlogged <glossterm>Relation</glossterm> are not
+      reflected in the <glossterm>WAL Log</glossterm>.  This disables
+      replication and crash recovery for these relations.
+     </para>
+     <para>
+      The primary use of unlogged tables is for storing
+      transient work data that must be shared across processes.
+     </para>
+     <para>
+      <glossterm>Temporary Table</glossterm>s are always unlogged.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-update">
+    <glossterm>Update</glossterm>
+    <glossdef>
+     <para>
+      A command used to modify <glossterm>Row</glossterm>s that may already
+      exist in a specified <glossterm>Table</glossterm>. It cannot create
+      or remove rows.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-update"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-user">
+    <glossterm>User</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Role</glossterm> that has the <literal>LOGIN</literal>
+      privilege is said to be a <glossterm>User</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-user-mapping">
+    <glossterm>User Mapping</glossterm>
+    <glossdef>
+     <para>
+      The translation of login credentials in the local
+      <glossterm>Database</glossterm> to credentials in a remote data system
+      defined by a <glossterm>Foreign Data Wrapper</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createusermapping"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-vacuum">
+    <glossterm>Vacuum</glossterm>
+    <glossdef>
+     <para>
+      The process of removing outdated <acronym>MVCC</acronym>
+      <glossterm>Tuple</glossterm>s from a <glossterm>Heap</glossterm> or 
+      <glossterm>Index</glossterm>. This can be initiated through the use of
+      the <command>VACUUM</command> command, but can also be handled automatically
+      via <glossterm>Autovacuum</glossterm> processes.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-vacuum"/> .
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-view">
+    <glossterm>View</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Relation</glossterm> that is defined by a
+      <command>SELECT</command> statement, but has no storage of its own.
+      Any time a query references a <glossterm>View</glossterm>, the
+      definition of the <glossterm>View</glossterm> is substituted into the
+      query as if the user had typed that subquery instead of the name of
+      the <glossterm>View</glossterm>.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="sql-createview"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-archiver">
+    <glossterm>WAL Archiver</glossterm>
+    <glossdef>
+     <para>
+      A process that saves copies of <glossterm>WAL File</glossterm>s,
+      for the purposes of creating backups or keeping
+      <glossterm>Replica</glossterm>s current.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="continuous-archiving"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-file">
+    <glossterm>WAL File</glossterm>
+    <glossdef>
+     <para>
+      <glossterm>WAL Record</glossterm>s are continously written to the end
+      of the current <glossterm>WAL File</glossterm>.  WAL files
+      as well as WAL records belong
+      to the complete <glossterm>Cluster</glossterm>, not to a single
+      <glossterm>Database</glossterm>. After a WAL file
+      is full, a new WAL file is
+      created, or, under certain conditions, one of the previous
+      <glossterm>WAL File</glossterm>s is renamed and reused.
+     </para>
+     <para>
+      The sequence of <glossterm>WAL Record</glossterm>s 
+      represents the sequence of changes that have taken place in the
+      <glossterm>Cluster</glossterm>.
+     </para>
+      <para>
+       For more information, see
+       <xref linkend="wal-internals"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+    <glossentry id="glossary-wal-log">
+    <glossterm>WAL Log</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-record">
+    <glossterm>WAL Record</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>WAL Record</glossterm> contains either new or changed
+      <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> data or
+      information about a <command>COMMIT</command>,
+      <command>ROLLBACK</command>, <command>SAVEPOINT</command>, or
+      <glossterm>Checkpointer</glossterm> operation. WAL records use a
+      non-printable binary format.
+     </para>
+      <para>
+       For more information, see
+       <xref linkend="wal-internals"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-segment">
+    <glossterm>WAL Segment</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-segment-file">
+    <glossterm>WAL Segment File</glossterm>
+    <glossdef>
+     <para>
+      See <glossterm>WAL File</glossterm>.
+     </para>
+    </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-wal-writer">
+   <glossterm>WAL Writer</glossterm>
+   <glossdef>
+    <para>
+     This process writes <glossterm>WAL Record</glossterm>s from
+     <glossterm>Shared Memory</glossterm> to 
+     <glossterm>WAL File</glossterm>s.
+    </para>
+      <para>
+       For more information, see
+       <xref linkend="runtime-config-wal"/>.
+     </para>
+   </glossdef>
+   </glossentry>
+
+   <glossentry id="glossary-window-function">
+    <glossterm>Window Function</glossterm>
+    <glossdef>
+     <para>
+      A type of <glossterm>Function</glossterm> similar to an
+      <glossterm>Aggregate</glossterm> in that it can derive its value from a
+      set of <glossterm>Row</glossterm>s in a <glossterm>Result
+      Set</glossterm>, while retaining the original source data.
+     </para>
+     <para>
+      For more information, see
+      <xref linkend="tutorial-window"/>.
+     </para>
+    </glossdef>
+   </glossentry>
+  </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 1f7bd32878..ba3d626102 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
   &docguide;
   &limits;
   &acronyms;
+  &glossary;
   &color;
 
  </part>
-- 
2.20.1

diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index eab14f3c9b..623922a4c3 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -36,10 +36,10 @@
    </glossentry>
 
    <glossentry id="glossary-analytic">
-    <glossterm>Analytic</glossterm>
+    <glossterm>Analytic Function</glossterm>
     <glossdef>
      <para>
-      A <glossterm>Function</glossterm> whose computed value can reference
+      A type of <glossterm>Function</glossterm>s whose result may be based on
       values found in nearby <glossterm>Row</glossterm>s of the same
       <glossterm>Result Set</glossterm>.
      </para>
@@ -59,12 +59,12 @@
       into smaller components.
      </para>
      <para>
+      <!-- better wording ??? '... cannot be partially processed; ...' -->
       In reference to an operation: an event that cannot be completed in
       part; it must either entirely succeed or entirely fail. For
       example, a series of <acronym>SQL</acronym> statements can be
       combined into a <glossterm>Transaction</glossterm>, and that
-      transaction is said to be atomic.
-      <glossterm>Atomic</glossterm>.
+      transaction is said to be <glossterm>Atomic</glossterm>.
      </para>
     </glossdef>
    </glossentry>
@@ -73,7 +73,7 @@
     <glossterm>Atomicity</glossterm>
     <glossdef>
      <para>
-      One of the <acronym>ACID</acronym> properties. This is the state of 
+      One of the <acronym>ACID</acronym> properties. This is the state of
       being <glossterm>Atomic</glossterm> in the operational/transactional sense.
      </para>
     </glossdef>
@@ -152,7 +152,7 @@
       A process that continuously writes dirty pages from
       <glossterm>Shared Memory</glossterm> to the file system.
       It wakes up periodically, but
-      works only for a short period in order to distribute expensive
+      works only for a short period in order to distribute its expensive
       <acronym>I/O</acronym> activity over time, instead of generating fewer
       larger <acronym>I/O</acronym> peaks which could block other processes.
      </para>
@@ -220,7 +220,7 @@
       Record</glossterm>s to the file system and creates a special
       checkpoint record. This process is initiated when predefined
       conditions are met, such as a specified amount of time has passed, or
-      a certain volume of records have been collected.
+      a certain volume of records has been collected.
      </para>
     </glossdef>
    </glossentry>
@@ -303,7 +303,7 @@
     <glossdef>
      <para>
       An established line of communication between a client process
-      and a server process. If the two involved processes reside on the
+      and a <glossterm>Backend Process</glossterm>. If the two involved processes reside on the
       same <glossterm>Server</glossterm>, then the connection can either use
       <acronym>TCP/IP</acronym> or Unix-domain sockets. Otherwise,
       only <acronym>TCP/IP</acronym> can be used.
@@ -470,7 +470,7 @@
       A type of <glossterm>Constraint</glossterm> defined on one or more
       <glossterm>Column</glossterm>s in a <glossterm>Table</glossterm> which
       requires the value(s) in those <glossterm>Column</glossterm>s to
-      identify exactly one <glossterm>Row</glossterm> in the specified
+      identify exactly one <glossterm>Row</glossterm> in another (or the same)
       <glossterm>Table</glossterm>.
      </para>
     </glossdef>
@@ -643,7 +643,7 @@
     <glossterm>Isolation</glossterm>
     <glossdef>
      <para>
-      One of the <acronym>ACID</acronym> properties. This means that concurrently running 
+      One of the <acronym>ACID</acronym> properties. This means that concurrently running
       <glossterm>Transaction</glossterm>s affect the database exactly as if they had been
       executed sequentially.
      </para>
@@ -795,6 +795,7 @@
     <glossterm>Partition</glossterm>
     <glossdef>
      <para>
+      In reference to a <glossterm>Table</glossterm>:
       A <glossterm>Table</glossterm> that can be queried directly,
       or via a partitioned table, which is a collection of
       sub-tables, each capable of holding one defined
@@ -802,9 +803,8 @@
       table in the collection.
      </para>
      <para>
-      When referring to an <glossterm>Analytic</glossterm>
-      <glossterm>Function</glossterm>: a partition is a definition
-      that identifies which neighboring
+      In reference to a <glossterm>Analytic Function</glossterm>:
+      a partition is a definition that identifies which neighboring
       <glossterm>Row</glossterm>s can be considered by the
       function.
      </para>
@@ -865,13 +865,13 @@
    <glossentry id="glossary-record">
     <glossterm>Record</glossterm>
     <glossdef>
-     <para>
-      See <glossterm>Tuple</glossterm>.
-     </para>
      <para>
       A single <glossterm>Row</glossterm> of a <glossterm>Table</glossterm>
       or other <glossterm>Relation</glossterm>.
      </para>
+     <para>
+      See <glossterm>Tuple</glossterm>.
+     </para>
     </glossdef>
    </glossentry>
 
@@ -880,6 +880,7 @@
     <glossdef>
      <para>
       A means of restricting data in one <glossterm>Relation</glossterm>
+      by a <glossterm>Foreign Key</glossterm>
       so that it must have matching data in another
       <glossterm>Relation</glossterm>.
      </para>
@@ -905,7 +906,7 @@
     <glossterm>Replica</glossterm>
     <glossdef>
      <para>
-      A <glossterm>Database</glossterm> that is paired with a 
+      A <glossterm>Database</glossterm> that is paired with a
       <glossterm>Master</glossterm>
       database and is maintaining a copy of some or
       all of the Master <glossterm>Database</glossterm>'s data. The primary
@@ -934,7 +935,7 @@
     <glossterm>Result Set</glossterm>
     <glossdef>
      <para>
-      A data structure transmitted from a <glossterm>Server</glossterm> to
+      A data structure transmitted from a <glossterm>Backend Process</glossterm> to
       client program upon the completion of a <acronym>SQL</acronym>
       command, usually a <command>SELECT</command> but it can be an
       <command>INSERT</command>, <command>UPDATE</command>, or
@@ -1068,8 +1069,8 @@
     <glossterm>Select</glossterm>
     <glossdef>
      <para>
-      The command used to query a <glossterm>Database</glossterm>. Normally,
-      <command>SELECT</command>s are not expected to modify the
+      The <acronym>SQL</acronym> command used to query a <glossterm>Database</glossterm>.
+      Normally, <command>SELECT</command>s are not expected to modify the
       <glossterm>Database</glossterm> in any way, but it is possible that
       <glossterm>Function</glossterm>s invoked within the query could have
       side effects that do modify data.
@@ -1333,7 +1334,8 @@
     <glossdef>
      <para>
       The condition of having no duplicate values in the same
-      <glossterm>Relation</glossterm>. Often used in the concept of
+      <glossterm>Column</glossterm> of a <glossterm>Relation</glossterm>.
+      Often used in the concept of
       <glossterm>Unique Index</glossterm>es.
      </para>
     </glossdef>
@@ -1361,9 +1363,9 @@
     <glossterm>Update</glossterm>
     <glossdef>
      <para>
-      A command used to modify <glossterm>Row</glossterm>s that may already
-      exist in a specified <glossterm>Table</glossterm>. It cannot create
-      or remove rows.
+      A <acronym>SQL</acronym> command used to modify <glossterm>Row</glossterm>s
+      that may already exist in a specified <glossterm>Table</glossterm>.
+      It cannot create or remove rows.
      </para>
      <para>
       For more information, see
@@ -1402,7 +1404,7 @@
     <glossdef>
      <para>
       The process of removing outdated <acronym>MVCC</acronym>
-      <glossterm>Tuple</glossterm>s from a <glossterm>Heap</glossterm> or 
+      <glossterm>Tuple</glossterm>s from a <glossterm>Heap</glossterm> or
       <glossterm>Index</glossterm>. This can be initiated through the use of
       the <command>VACUUM</command> command, but can also be handled automatically
       via <glossterm>Autovacuum</glossterm> processes.
@@ -1436,7 +1438,7 @@
     <glossterm>WAL Archiver</glossterm>
     <glossdef>
      <para>
-      A process that saves copies of <glossterm>WAL File</glossterm>s,
+      A process that saves copies of <glossterm>WAL File</glossterm>s
       for the purposes of creating backups or keeping
       <glossterm>Replica</glossterm>s current.
      </para>
@@ -1461,7 +1463,7 @@
       <glossterm>WAL File</glossterm>s is renamed and reused.
      </para>
      <para>
-      The sequence of <glossterm>WAL Record</glossterm>s 
+      The sequence of <glossterm>WAL Record</glossterm>s
       represents the sequence of changes that have taken place in the
       <glossterm>Cluster</glossterm>.
      </para>
@@ -1522,7 +1524,7 @@
    <glossdef>
     <para>
      This process writes <glossterm>WAL Record</glossterm>s from
-     <glossterm>Shared Memory</glossterm> to 
+     <glossterm>Shared Memory</glossterm> to
      <glossterm>WAL File</glossterm>s.
     </para>
       <para>

diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 1043d0f7ab..cf21ef857e 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..3c417f2fd3
--- /dev/null
+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,1526 @@
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+  This is a list of terms and their meaning in the context of
+  <productname>PostgreSQL</productname> and relational database
+  systems in general.
+ </para>
+
+ <glosslist>
+  <glossentry id="glossary-aggregating">
+   <glossterm>Aggregating</glossterm>
+   <glossdef>
+    <para>
+     The act of combining a collection of data (input) values into
+     a single output value, which may not be of the same type as the
+     input values.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-aggregate">
+   <glossterm>Aggregate Function</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-function">function</glossterm> that
+     combines multiple input values,
+     for example by counting, averaging or adding them all together,
+     yielding a single output value.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="functions-aggregate"/>.
+    </para>
+    <glossseealso otherterm="glossary-window-function" />
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Analytic Function</glossterm>
+   <glosssee otherterm="glossary-window-function" />
+  </glossentry>
+
+  <glossentry id="glossary-atomic">
+   <glossterm>Atomic</glossterm>
+   <glossdef>
+    <para>
+     In reference to a <glossterm linkend="glossary-datum">datum</glossterm>:
+     the fact that its value that cannot be broken down into smaller
+     components.
+    </para>
+   </glossdef>
+   <glossdef>
+    <para>
+     In reference to a
+     <glossterm linkend="glossary-transaction">database transaction</glossterm>:
+     the fact that all the operations in the transaction either complete as
+     a whole, or none of them become visible.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-atomicity">
+   <glossterm>Atomicity</glossterm>
+   <glossdef>
+    <para>
+     One of the <acronym>ACID</acronym> properties. This is the state of
+     being <glossterm>Atomic</glossterm> in the operational/transactional sense.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-attribute">
+   <glossterm>Attribute</glossterm>
+   <glossdef>
+    <para>
+     An element with a certain name and data type found within a
+     <glossterm>Tuple</glossterm> or <glossterm>Table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-autovacuum">
+   <glossterm>Autovacuum</glossterm>
+   <glossdef>
+    <para>
+     Background processes that routinely perform
+     <glossterm>Vacuum</glossterm> and <glossterm>Analyze</glossterm>
+     operations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="routine-vacuuming"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-backend-process">
+   <glossterm>Backend Process</glossterm>
+   <glossdef>
+    <para>
+     Processes of an <glossterm>Instance</glossterm> which act on behalf of
+     client <glossterm>Connection</glossterm>s and handle their requests.
+    </para>
+    <para>
+     (Don't confuse this term with the similar terms
+     <glossterm>Background Worker</glossterm> or
+     <glossterm>Background Writer</glossterm>).
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-background-worker">
+   <glossterm>Background Worker</glossterm>
+   <glossdef>
+    <para>
+     Individual processes within an <glossterm>Instance</glossterm>, which
+     run system- or user-supplied code.  A typical use case is a process
+     which handles parts of an <acronym>SQL</acronym> query to take
+     advantage of parallel execution on servers with multiple
+     <acronym>CPU</acronym>s.
+   </para>
+   <para>
+    For more information, see
+    <xref linkend="bgworker"/>.
+   </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-background-writer">
+   <glossterm>Background Writer</glossterm>
+   <glossdef>
+    <para>
+     A process that continuously writes dirty pages from
+     <glossterm>Shared Memory</glossterm> to the file system.
+     It wakes up periodically, but
+     works only for a short period in order to distribute its expensive
+     <acronym>I/O</acronym> activity over time, instead of generating fewer
+     larger <acronym>I/O</acronym> peaks which could block other processes.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-resource"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-cast">
+   <glossterm>Cast</glossterm>
+   <glossdef>
+    <para>
+     A conversion of a <glossterm>Datum</glossterm> from its current data
+     type to another data type.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-catalog">
+   <glossterm>Catalog</glossterm>
+   <glossdef>
+    <para>
+     The <acronym>SQL</acronym> standard uses this term to
+     indicate what is called a <glossterm>Database</glossterm> in
+     <productname>PostgreSQL</productname>'s terminology.
+    </para>
+    <para>
+     This should not be confused with the
+     <glossterm>System Catalog</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-check-constraint">
+   <glossterm>Check Constraint</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm>Constraint</glossterm> defined on a
+     <glossterm>Relation</glossterm> which restricts the values allowed in
+     one or more <glossterm>Attribute</glossterm>s. The <glossterm>Check
+     Constraint</glossterm> can make reference to any
+     attribute in the
+     <glossterm>Relation</glossterm>, but cannot reference other
+     <glossterm>Row</glossterm>s of the same
+     relation or other relations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-constraints"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-checkpointer">
+   <glossterm>Checkpointer (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that writes dirty pages to the file system and creates a special
+     checkpoint WAL record. This process is initiated when predefined
+     conditions are met, such as a specified amount of time has passed, or
+     a certain volume of records has been collected.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-checkpoint">
+   <glossterm>Checkpoint</glossterm>
+   <glossdef>
+    <para>
+     A point in time when all older dirty pages of the
+     <glossterm>Shared Memory</glossterm>, all older <glossterm>WAL Record</glossterm>s,
+     and a special <glossterm>Checkpoint record</glossterm> have been written
+     and flushed to disk.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-checkpoint"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-cluster">
+   <glossterm>Cluster</glossterm>
+   <glossdef>
+    <para>
+     A group of <glossterm>Database</glossterm>s plus their
+     <glossterm>Global SQL Object</glossterm>s. The
+     <glossterm>Cluster</glossterm> is managed by exactly one
+     <glossterm>Instance</glossterm>. A newly created
+     <glossterm>Cluster</glossterm> will have three
+     <glossterm>Database</glossterm>s created automatically. They are
+     <literal>template0</literal>, <literal>template1</literal>, and
+     <literal>postgres</literal>. It is expected that an application will
+     create one or more additional <glossterm>Database</glossterm>s aside
+     from these three.
+    </para>
+    <para>
+     Don't confuse the <productname>PostgreSQL</productname>-specific term
+     <glossterm>Cluster</glossterm> with the SQL command
+     <literal>CLUSTER</literal>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-column">
+   <glossterm>Column</glossterm>
+   <glossdef>
+    <para>
+     An <glossterm>Attribute</glossterm> found in a
+     <glossterm>Table</glossterm> or <glossterm>View</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-commit">
+   <glossterm>Commit</glossterm>
+   <glossdef>
+    <para>
+     The act of finalizing a <glossterm>Transaction</glossterm> within the
+     <glossterm>Database</glossterm>.
+    </para>
+   <para>
+    For more information, see
+    <xref linkend="sql-commit"/>.
+   </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-concurrency">
+   <glossterm>Concurrency</glossterm>
+   <glossdef>
+    <para>
+     The concept that multiple independent operations happen within the
+     <glossterm>Database</glossterm> at the same time.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-connection">
+   <glossterm>Connection</glossterm>
+   <glossdef>
+    <para>
+     An established line of communication between a client process
+     and a <glossterm>Backend Process</glossterm>. If the two involved processes reside on the
+     same <glossterm>Server</glossterm>, then the connection can either use
+     <acronym>TCP/IP</acronym> or Unix-domain sockets. Otherwise,
+     only <acronym>TCP/IP</acronym> can be used.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-connection"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-consistency">
+   <glossterm>Consistency</glossterm>
+   <glossdef>
+    <para>
+     One of the <acronym>ACID</acronym> properties. This means that the database
+     is always in compliance with its own rules such as <glossterm>Table</glossterm>
+     structure, <glossterm>Constraint</glossterm>s,
+     <glossterm>Uniqueness</glossterm>, etc.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-constraint">
+   <glossterm>Constraint</glossterm>
+   <glossdef>
+    <para>
+     A restriction on the values of data allowed within a
+     <glossterm>Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-constraints"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Data Area</glossterm>
+   <glosssee otherterm="glossary-data-directory" />
+  </glossentry>
+
+  <glossentry id="glossary-data-directory">
+   <glossterm>Data Directory</glossterm>
+   <glossdef>
+    <para>
+     The base directory on the filesystem of a
+     <glossterm>Server</glossterm> that contains all data files and
+     subdirectories associated with a <glossterm>Cluster</glossterm> with
+     the exception of <glossterm>Tablespace</glossterm>s. The environment
+     variable <literal>PGDATA</literal> often &mdash; but not always &mdash;
+     refers to the <glossterm>Data Directory</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="storage-file-layout"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-database">
+   <glossterm>Database</glossterm>
+   <glossdef>
+    <para>
+     A named collection of <glossterm>SQL Object</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Database Server</glossterm>
+   <glosssee otherterm="glossary-instance" />
+  </glossentry>
+
+  <glossentry id="glossary-datum">
+   <glossterm>Datum</glossterm>
+   <glossdef>
+    <para>
+     The internal representation of one value of a <acronym>SQL</acronym>
+     data type.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-delete">
+   <glossterm>Delete</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command which removes
+     <glossterm>Row</glossterm>s from a given <glossterm>Table</glossterm>
+     or <glossterm>Relation</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-delete"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-durability">
+   <glossterm>Durability</glossterm>
+   <glossdef>
+    <para>
+     One of the <acronym>ACID</acronym> properties. This is the assurance that once a
+     <glossterm>Transaction</glossterm> has been <glossterm>Committed</glossterm>, the
+     data will remain even after a system failure or crash.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-file-segment">
+   <glossterm>File Segment</glossterm>
+   <glossdef>
+    <para>
+     A physical file which stores data for a given
+     <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> object.
+     <glossterm>File Segment</glossterm>s are limited in size by a
+     configuration value and if that size is exceeded, it will be split
+     into multiple physical files.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="storage-file-layout"/>.
+    </para>
+    <para>
+     (Don't confuse this term with the similar term
+     <glossterm>WAL Segment</glossterm>).
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-data-wrapper">
+   <glossterm>Foreign Data Wrapper</glossterm>
+   <glossdef>
+    <para>
+     A means of representing data that is not contained in the local
+     <glossterm>Database</glossterm> so that it appears as if were in local
+     <glossterm>Table</glossterm>(s). With a Foreign Data Wrapper it is
+     possible to define a <glossterm>Foreign Server</glossterm> and
+     <glossterm>Foreign Table</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createforeigndatawrapper"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-key">
+   <glossterm>Foreign Key</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm>Constraint</glossterm> defined on one or more
+     <glossterm>Column</glossterm>s in a <glossterm>Table</glossterm> which
+     requires the value(s) in those <glossterm>Column</glossterm>s to
+     identify exactly one <glossterm>Row</glossterm> in another (or the same)
+     <glossterm>Table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-server">
+   <glossterm>Foreign Server</glossterm>
+   <glossdef>
+    <para>
+     A named collection of <glossterm>Foreign Table</glossterm>s which all
+     use the same <glossterm>Foreign Data Wrapper</glossterm> and have
+     other configuration values in common.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createserver"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-table">
+   <glossterm>Foreign Table</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Relation</glossterm> which appears to have
+     <glossterm>Row</glossterm>s and <glossterm>Column</glossterm>s similar
+     to a regular <glossterm>Table</glossterm>, but will forward requests
+     for data through its <glossterm>Foreign Data Wrapper</glossterm>,
+     which will return <glossterm>Result Set</glossterm>s structured
+     according to the definition of the <glossterm>Foreign Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createforeigntable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-function">
+   <glossterm>Function</glossterm>
+   <glossdef>
+    <para>
+     Any defined transformation of data. Many functions are already defined
+     within <productname>PostgreSQL</productname> itself, but user-defined
+     ones can also be added.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createfunction"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-global-sql-object">
+   <glossterm>Global SQL Object</glossterm>
+   <glossdef>
+    <para>
+     <glossterm>SQL Object</glossterm>s which do not belong to a specific
+     <glossterm>Schema</glossterm>.
+    </para>
+    <para>
+     Objects that exist at the <glossterm>Database</glossterm> level
+     include Extensions such as
+     <glossterm>Foreign Data Wrapper</glossterm>s.
+    </para>
+    <para>
+     Objects that exist at the <glossterm>Cluster</glossterm> level
+     include <glossterm>Role</glossterm>s,
+     <glossterm>Tablespace</glossterm>s,
+     <glossterm>Replication</glossterm> origins, and subscriptions
+     for logical replication.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-grant">
+   <glossterm>Grant</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command that is used to allow
+     <glossterm>User</glossterm>s or <glossterm>Role</glossterm>s to access
+     specific objects within the <glossterm>Database</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-grant"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-heap">
+   <glossterm>Heap</glossterm>
+   <glossdef>
+    <para>
+     Contains the values of <glossterm>Row</glossterm> attributes
+     (i.e. the data). The <glossterm>Heap</glossterm> is realized within
+     <glossterm>Database</glossterm> files.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Host</glossterm>
+   <glosssee otherterm="glossary-server" />
+  </glossentry>
+
+  <glossentry id="glossary-index">
+   <glossterm>Index</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Relation</glossterm> that contains data derived from a
+     <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> types
+     such as a <glossterm>Materialized View</glossterm>). Its internal
+     structure supports fast retrieval of and access to the original
+     data.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createindex"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-insert">
+   <glossterm>Insert</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command used to add new data into a
+     <glossterm>Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-insert"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-instance">
+   <glossterm>Instance</glossterm>
+   <glossdef>
+    <para>
+     An <glossterm>Instance</glossterm> is a group of processes plus their
+     common <glossterm>Shared Memory</glossterm> running on a single
+     <glossterm>Server</glossterm>. The <glossterm>Instance</glossterm>
+     handles all key features of a <acronym>DBMS</acronym>: read and write
+     access to files and shared memory, assurance of
+     the <acronym>ACID</acronym> paradigm, <acronym>MVCC</acronym>,
+     <glossterm>Connection</glossterm>s to client programs, backup,
+     recovery, replication, privileges, etc.
+    </para>
+    <para>
+     An <glossterm>Instance</glossterm> manages exactly one
+     <glossterm>Cluster</glossterm>.
+    </para>
+    <para>
+     Many <glossterm>Instance</glossterm>s can run on the same server as
+     long as their <acronym>TCP/IP</acronym> ports do not conflict.
+     Different instances on a server may use the
+     same or different versions of <productname>PostgreSQL</productname>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-isolation">
+   <glossterm>Isolation</glossterm>
+   <glossdef>
+    <para>
+     One of the <acronym>ACID</acronym> properties. This means that concurrently running
+     <glossterm>Transaction</glossterm>s affect the database exactly as if they had been
+     executed sequentially.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-join">
+   <glossterm>Join</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> keyword used in <command>SELECT</command> statements for
+     combining data from multiple <glossterm>Relation</glossterm>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-key">
+   <glossterm>Key</glossterm>
+   <glossdef>
+    <para>
+     A means of identifying a <glossterm>Row</glossterm> within a
+     <glossterm>Table</glossterm> or <glossterm>Relation</glossterm> by
+     values contained within one or more <glossterm>Attribute</glossterm>s
+     in that <glossterm>Table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-lock">
+   <glossterm>Lock</glossterm>
+   <glossdef>
+    <para>
+     A mechanism that allows a process to limit or prevent simultaneous
+     access to a resource.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-log-file">
+   <glossterm>Log File</glossterm>
+   <glossdef>
+    <para>
+     <glossterm>Log File</glossterm>s contain human-readable text lines about
+     events. Examples include login failures, long-running queries, etc.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="logfile-maintenance"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-logger">
+   <glossterm>Logger (process)</glossterm>
+   <glossdef>
+    <para>
+     If activated, the
+     <glossterm>Logger</glossterm> process
+     writes information about database events into the current
+     <glossterm>Log File</glossterm>. When reaching certain time- or
+     volume-dependent criteria, a new log file is created.
+     Also called <firstterm>syslogger</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-logging"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-log-record">
+   <glossterm>Log Record</glossterm>
+    <glossdef>
+     <para>
+      Archaic term for a <glossterm>WAL Record</glossterm>.
+     </para>
+    </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-logged">
+   <glossterm>Logged</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Table</glossterm> is considered
+     <glossterm>Logged</glossterm> if changes to it are sent to the
+     <glossterm>WAL Log</glossterm>. By default, all regular
+     <glossterm>Table</glossterm>s are <glossterm>Logged</glossterm>. A
+     table can be specified as <glossterm>Unlogged</glossterm> either at
+     creation time or via the <command>ALTER TABLE</command> command.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-master">
+   <glossterm>Master</glossterm>
+   <glossdef>
+    <para>
+     When two or more <glossterm>Database</glossterm>s are linked via
+     <glossterm>Replication</glossterm>, the <glossterm>Server</glossterm>
+     that is considered the authoritative source of information is called
+     the <glossterm>Master</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-materialized">
+   <glossterm>Materialized</glossterm>
+   <glossdef>
+    <para>
+     The act of storing information rather than just the method of accessing
+     the information. This term is used in <glossterm>Materialized
+     View</glossterm>s, meaning that the data derived from the
+     <glossterm>View</glossterm> is actually stored on disk separately from
+     the sources of that data. When using the term
+     <glossterm>Materialized</glossterm> to refer to
+     multi-step queries, it means that the data of a given step is stored
+     in memory, but that storage may spill over onto disk.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-materialized-view">
+   <glossterm>Materialized View</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Relation</glossterm> that is defined in the same way that
+     a <glossterm>View</glossterm> is, but stores data in the same way
+     that a <glossterm>Table</glossterm> does. It cannot be modified via
+     <command>INSERT</command>, <command>UPDATE</command>, or
+     <command>DELETE</command> operations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-creatematerializedview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-null">
+   <glossterm>Null</glossterm>
+   <glossdef>
+    <para>
+     A concept of non-existence that is a central tenet of Relational
+     Database Theory. It represents the absence of value.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-partition">
+   <glossterm>Partition</glossterm>
+   <glossdef>
+    <para>
+     In reference to a <glossterm>Table</glossterm>:
+     A <glossterm>Table</glossterm> that can be queried directly,
+     or via a partitioned table, which is a collection of
+     sub-tables, each capable of holding one defined
+     subset of information that does not overlap with any other
+     table in the collection.
+    </para>
+    <para>
+     In reference to a <glossterm>Analytic Function</glossterm>:
+     a partition is a definition that identifies which neighboring
+     <glossterm>Row</glossterm>s can be considered by the
+     function.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-postmaster">
+   <glossterm>Postmaster</glossterm>
+   <glossdef>
+    <para>
+      The very first process of an <glossterm>Instance</glossterm>. It
+      starts the other processes and creates
+      <glossterm>Backend Process</glossterm>es on demand.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="server-start"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-primary-key">
+   <glossterm>Primary Key</glossterm>
+   <glossdef>
+    <para>
+     A special case of a <glossterm>Unique Index</glossterm> defined on a
+     <glossterm>Table</glossterm> or other <glossterm>Relation</glossterm>
+     that also guarantees that all of the <glossterm>Attribute</glossterm>s
+     within the <glossterm>Primary Key</glossterm> do not have
+     <glossterm>Null</glossterm> values.  As the name implies, there can be
+     only one <glossterm>Primary Key</glossterm> per
+     table, though it is possible to have multiple
+     unique indexes that also have no null-capable attributes.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-procedure">
+   <glossterm>Procedure</glossterm>
+   <glossdef>
+    <para>
+     A defined set of instructions for manipulating data within a
+     <glossterm>Database</glossterm>. A <glossterm>Procedure</glossterm> can
+     be written in a variety of programming languages. They may seem
+     similar to <glossterm>Function</glossterm>s, but are different in that
+     they must be invoked via the <command>CALL</command> command rather
+     than the <command>SELECT</command> or <command>PERFORM</command>
+     commands, and they are allowed to make transactional statements such
+     as <command>COMMIT</command> and <command>ROLLBACK</command>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createprocedure"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Record</glossterm>
+   <glosssee otherterm="glossary-tuple" />
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Recycling</glossterm>
+   <glosssee otherterm="glossary-wal-file" />
+  </glossentry>
+
+  <glossentry id="glossary-referential-integrity">
+   <glossterm>Referential Integrity</glossterm>
+   <glossdef>
+    <para>
+     A means of restricting data in one <glossterm>Relation</glossterm>
+     by a <glossterm>Foreign Key</glossterm>
+     so that it must have matching data in another
+     <glossterm>Relation</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-relation">
+   <glossterm>Relation</glossterm>
+   <glossdef>
+    <para>
+     The generic term for all objects in a <glossterm>Database</glossterm>
+     that have a name and a list of <glossterm>Attribute</glossterm>s
+     defined in a specific order. <glossterm>Table</glossterm>s,
+     <glossterm>View</glossterm>s, <glossterm>Foreign Table</glossterm>s,
+     <glossterm>Materialized View</glossterm>s, and
+     <glossterm>Index</glossterm>es are all
+     <glossterm>Relation</glossterm>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-replica">
+   <glossterm>Replica</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Database</glossterm> that is paired with a
+     <glossterm>Master</glossterm>
+     database and is maintaining a copy of some or
+     all of the Master <glossterm>Database</glossterm>'s data. The primary
+     reasons for doing this are to allow for greater access to that data,
+     and to maintain availability of the data in the event that the
+     <glossterm>Master</glossterm> becomes unavailable.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-replication">
+   <glossterm>Replication</glossterm>
+   <glossdef>
+    <para>
+      The act of reproducing data on one <glossterm>Server</glossterm> onto
+      another server called a <glossterm>Replica</glossterm>. This can take the
+      form of Physical <glossterm>Replication</glossterm>, where all file
+      changes from one server are copied verbatim,
+      or Logical <glossterm>Replication</glossterm> where a defined subset
+      of data changes are conveyed.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-result-set">
+   <glossterm>Result Set</glossterm>
+   <glossdef>
+    <para>
+     A data structure transmitted from a <glossterm>Backend Process</glossterm> to
+     client program upon the completion of a <acronym>SQL</acronym>
+     command, usually a <command>SELECT</command> but it can be an
+     <command>INSERT</command>, <command>UPDATE</command>, or
+     <command>DELETE</command> command if the <literal>RETURNING</literal>
+     clause is specified. The data structure consists of zero or more
+     <glossterm>Row</glossterm>s with the same ordered set of
+     <glossterm>Attribute</glossterm>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-revoke">
+   <glossterm>Revoke</glossterm>
+   <glossdef>
+    <para>
+     A command to prevent access to a named set of
+     <glossterm>Database</glossterm> objects for a named list of
+     <glossterm>User</glossterm>s and <glossterm>Role</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-revoke"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-role">
+   <glossterm>Role</glossterm>
+   <glossdef>
+    <para>
+     A collection of access privileges to the
+     <glossterm>Database</glossterm>. <glossterm>Role</glossterm>s are
+     themselves a privilege that can be granted to other roles. This is
+     often done for convenience or to ensure completeness when multiple
+     <glossterm>User</glossterm>s need the same privileges.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createrole"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-rollback">
+   <glossterm>Rollback</glossterm>
+   <glossdef>
+    <para>
+     A command to undo all of the operations performed since the beginning
+     of a <glossterm>Transaction</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-rollback"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Row</glossterm>
+   <glosssee otherterm="glossary-tuple" />
+  </glossentry>
+
+  <glossentry id="glossary-savepoint">
+   <glossterm>Savepoint</glossterm>
+   <glossdef>
+    <para>
+     A special mark inside the sequence of steps in a
+     <glossterm>Transaction</glossterm>. Data modifications after this
+     point in time may be reverted to the time of the savepoint.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-savepoint"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-schema">
+   <glossterm>Schema</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Schema</glossterm> is a namespace for
+     <glossterm>SQL object</glossterm>s, which all reside in the same
+     <glossterm>database</glossterm>.  Each <glossterm>SQL
+     object</glossterm> must reside in exactly one
+     <glossterm>Schema</glossterm>.
+    </para>
+    <para>
+     In general, the names of <glossterm>SQL Object</glossterm>s in the
+     schema are unique &mdash; even across different types of objects.  The lone
+     exception is the case of <glossterm>Unique</glossterm>
+     <glossterm>Constraint</glossterm>s, in which case there
+     <emphasis>must</emphasis> be a <glossterm>Unique Index</glossterm>
+     with the same name and <glossterm>Schema</glossterm> as the
+     <glossterm>Constraint</glossterm>.  There is no restriction on reusing
+     a name in multiple <glossterm>Schema</glossterm>s.
+    </para>
+    <para>
+     Many <glossterm>SQL Object</glossterm>s reside in the default
+     <glossterm>Schema</glossterm> <literal>public</literal>, but it is
+     expected that more schemas are created to hold application-specific
+     <glossterm>SQL Object</glossterm>s.
+    </para>
+    <para>
+     More generically, the term <glossterm>Schema</glossterm> is used to
+     mean all data descriptions (<glossterm>Table</glossterm> definitions,
+     <glossterm>Constraint</glossterm>s, comments) for a given
+     <glossterm>Database</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-schemas"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Segment</glossterm>
+   <glosssee otherterm="glossary-file-segment" />
+  </glossentry>
+
+  <glossentry id="glossary-select">
+   <glossterm>Select</glossterm>
+   <glossdef>
+    <para>
+     The <acronym>SQL</acronym> command used to query a <glossterm>Database</glossterm>.
+     Normally, <command>SELECT</command>s are not expected to modify the
+     <glossterm>Database</glossterm> in any way, but it is possible that
+     <glossterm>Function</glossterm>s invoked within the query could have
+     side effects that do modify data.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-select"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-serializable">
+   <glossterm>Serializable</glossterm>
+   <glossdef>
+    <para>
+     Transactions defined as <literal>SERIALIZABLE</literal> are unable to
+     see changes made within other transactions. In effect, for the
+     initializing session the entire <glossterm>Database</glossterm>
+     appears to be frozen for the duration of the
+     <glossterm>Transaction</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-server">
+   <glossterm>Server</glossterm>
+   <glossdef>
+    <para>
+     The term <glossterm>Server</glossterm> denotes real hardware, a
+     container, or a Virtual Machine.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-session">
+   <glossterm>Session</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Connection</glossterm> to the <glossterm>Database</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-sequence">
+   <glossterm>Sequence</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Database</glossterm> object which represents the
+     mathematical concept of a numerical integral sequence. It can be
+     thought of as a <glossterm>Table</glossterm> with exactly one
+     <glossterm>Row</glossterm> and one <glossterm>Column</glossterm>. The
+     value stored is known as the current value. A
+     <glossterm>Sequence</glossterm> has a defined direction (usually
+     increasing) and an interval step (usually 1).  Whenever the
+     <literal>NEXTVAL</literal> pseudo-column of a
+     <glossterm>Sequence</glossterm> is accessed, the current value is moved
+     in the defined direction by the defined interval step, that value
+     is returned to the invoking query, and the current value of the
+     sequence is updated to reflect the new value. The value can be updated
+     multiple times in a single query, the net effect being that each row
+     selected will have a different value. Values taken from a
+     <glossterm>Sequence</glossterm> are never reverted, even in the case of
+     a <glossterm>Rollback</glossterm>, which means that the
+     <glossterm>Sequence</glossterm> will never generate the same number twice,
+     which makes it useful for generating
+     <glossterm>Primary Key</glossterm> values.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createsequence"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-shared-memory">
+   <glossterm>Shared Memory</glossterm>
+   <glossdef>
+    <para>
+     <acronym>RAM</acronym> which is used by the processes common to an
+     <glossterm>Instance</glossterm>. It mirrors parts of
+     <glossterm>Database</glossterm> files, provides an area for
+     <glossterm>WAL Record</glossterm>s, and stores additional common
+     information. Note that <glossterm>Shared Memory</glossterm> belongs to
+     the complete <glossterm>Instance</glossterm>, not to a single
+     <glossterm>Database</glossterm>.
+    </para>
+    <para>
+     <glossterm>Shared Memory</glossterm> is organized into pages. If a
+     page is modified, it is called a dirty page until it is written back
+     to the file system.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-resource-memory"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-sql-object">
+   <glossterm>SQL Object</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Table</glossterm>, <glossterm>View</glossterm>,
+      <glossterm>Materialized View</glossterm>,
+      <glossterm>Index</glossterm>, <glossterm>Constraint</glossterm>,
+      <glossterm>Sequence</glossterm>, <glossterm>Function</glossterm>,
+      <glossterm>Procedure</glossterm>, <glossterm>Trigger</glossterm>,
+      data type, or operator. Every <glossterm>SQL Object</glossterm>
+      belongs to exactly one <glossterm>Schema</glossterm>.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-stats-collector">
+   <glossterm>Stats Collector</glossterm>
+   <glossdef>
+    <para>
+     This process collects statistical information about the
+     <glossterm>Cluster</glossterm>'s activities.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="monitoring-stats"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-system-catalog">
+   <glossterm>System Catalog</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm>Table</glossterm>s and
+     <glossterm>View</glossterm>s which describe the structure of all
+     <acronym>SQL</acronym> objects of the <glossterm>Database</glossterm>
+     and the <glossterm>Global SQL Object</glossterm>s of the
+     <glossterm>Cluster</glossterm>. The <glossterm>System
+     Catalog</glossterm> resides in the schema
+     <literal>pg_catalog</literal>. Main parts are mirrored as
+     <glossterm>View</glossterm>s in the <glossterm>Schema</glossterm>
+     <literal>information_schema</literal>.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="ddl-schemas"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-table">
+   <glossterm>Table</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm>Tuple</glossterm>s (also known as
+     <glossterm>Row</glossterm>s or <glossterm>Record</glossterm>s) having
+     a common data structure (the same number of
+     <glossterm>Attribute</glossterm>s, in the same order, having the same
+     name and type per position). A <glossterm>Table</glossterm> is the
+     most common form of <glossterm>Relation</glossterm> in
+     <productname>PostgreSQL</productname>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-tablespace">
+   <glossterm>Tablespace</glossterm>
+   <glossdef>
+    <para>
+     A named location on the server filesystem. All <glossterm>SQL Object</glossterm>s
+     which require storage beyond their definition in the
+     <glossterm>System Catalog</glossterm>
+     must belong to a single tablespace.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-tablespaces"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-temporary-tables">
+   <glossterm>Temporary Table</glossterm>
+   <glossdef>
+    <para>
+     <glossterm>Table</glossterm>s that exist either for the lifetime of a
+     <glossterm>Session</glossterm> or a
+     <glossterm>Transaction</glossterm>, as specified at the time of creation. The
+     data in them is not visible to other sessions,
+     and is not <glossterm>Logged</glossterm>.
+     <glossterm>Temporary Table</glossterm>s are often used to store
+     intermediate data for a multi-step operation.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-transaction">
+   <glossterm>Transaction</glossterm>
+   <glossdef>
+    <para>
+     A combination of commands that must act as a single
+     <glossterm>Atomic</glossterm> command: they all succeed or all fail
+     as a single unit, and their effects are not visible to other
+     <glossterm>Session</glossterm>s until
+     the <glossterm>Transaction</glossterm> is complete.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="transaction-iso"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-trigger">
+   <glossterm>Trigger</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Function</glossterm> which can be defined to execute
+     whenever a certain operation (<command>INSERT</command>,
+     <command>UPDATE</command>, <command>DELETE</command>,
+     <command>TRUNCATE</command>) is applied to a <glossterm>Relation</glossterm>.
+     A <glossterm>Trigger</glossterm>
+     executes within the same <glossterm>Transaction</glossterm> as the
+     statement which invoked it, and if the <glossterm>Function</glossterm>
+     fails, then the invoking statement also fails.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtrigger"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-tuple">
+   <glossterm>Tuple</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm>Attribute</glossterm>s in a fixed order.
+     That order may be defined by the <glossterm>Table</glossterm> where
+     the <glossterm>Tuple</glossterm> is found, in which case the
+     <glossterm>Tuple</glossterm> is often called a
+     <glossterm>Row</glossterm> or <glossterm>Record</glossterm>. It may
+     also be defined by the structure of a
+     <glossterm>Result Set</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-unique">
+   <glossterm>Unique</glossterm>
+   <glossdef>
+    <para>
+     The condition of having no duplicate values in the same
+     <glossterm>Column</glossterm> of a <glossterm>Relation</glossterm>.
+     Often used in the concept of
+     <glossterm>Unique Index</glossterm>es.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-unlogged">
+   <glossterm>Unlogged</glossterm>
+   <glossdef>
+    <para>
+     Changes to an unlogged <glossterm>Relation</glossterm> are not
+     reflected in the <glossterm>WAL Log</glossterm>.  This disables
+     replication and crash recovery for these relations.
+    </para>
+    <para>
+     The primary use of unlogged tables is for storing
+     transient work data that must be shared across processes.
+    </para>
+    <para>
+     <glossterm>Temporary Table</glossterm>s are always unlogged.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-update">
+   <glossterm>Update</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command used to modify <glossterm>Row</glossterm>s
+     that may already exist in a specified <glossterm>Table</glossterm>.
+     It cannot create or remove rows.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-update"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-user">
+   <glossterm>User</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Role</glossterm> that has the <literal>LOGIN</literal>
+     privilege is said to be a <glossterm>User</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-user-mapping">
+   <glossterm>User Mapping</glossterm>
+   <glossdef>
+    <para>
+     The translation of login credentials in the local
+     <glossterm>Database</glossterm> to credentials in a remote data system
+     defined by a <glossterm>Foreign Data Wrapper</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createusermapping"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-vacuum">
+   <glossterm>Vacuum</glossterm>
+   <glossdef>
+    <para>
+     The process of removing outdated <acronym>MVCC</acronym>
+     <glossterm>Tuple</glossterm>s from a <glossterm>Heap</glossterm> or
+     <glossterm>Index</glossterm>. This can be initiated through the use of
+     the <command>VACUUM</command> command, but can also be handled automatically
+     via <glossterm>Autovacuum</glossterm> processes.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-vacuum"/> .
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-view">
+   <glossterm>View</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Relation</glossterm> that is defined by a
+     <command>SELECT</command> statement, but has no storage of its own.
+     Any time a query references a <glossterm>View</glossterm>, the
+     definition of the <glossterm>View</glossterm> is substituted into the
+     query as if the user had typed that subquery instead of the name of
+     the <glossterm>View</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal-archiver">
+   <glossterm>WAL Archiver (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that saves copies of <glossterm>WAL File</glossterm>s
+     for the purposes of creating backups or keeping
+     <glossterm>Replica</glossterm>s current.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="continuous-archiving"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal-file">
+   <glossterm>WAL File</glossterm>
+   <glossdef>
+    <para>
+     Each of the numerically-numbered files that provide storage space for
+     <glossterm linkend="glossary-wal">WAL</glossterm>.
+     The files are all of the same predefined size
+     and are written in sequential order, interspersing changes
+     as they occur in multiple simultaneous sessions.
+     If the system crashes, the files are read in order, and each of the
+     changes are replayed to restore the system to the state as it was
+     before the crash.
+    </para>
+    <para>
+     Each WAL file can be released after a
+     <glossterm linkend="glossary-checkpoint">checkpoint</glossterm>
+     writes all the changes in it to the corresponding data files.
+     Releasing the file can be done either by deleting it, or by changing its
+     name so that it will be used in the future, which is called
+     <firstterm>recycling</firstterm>.
+    </para>
+
+    <para>
+     For more information, see
+     <xref linkend="wal-internals"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>WAL</glossterm>
+   <glosssee otherterm="glossary-wal" />
+  </glossentry>
+
+  <glossentry id="glossary-wal-record">
+   <glossterm>WAL Record</glossterm>
+   <glossdef>
+    <para>
+     A low-level description of an individual data change.
+     It contains sufficient information for the data change to be
+     re-executed (<firstterm>replayed</firstterm>) in case a system failure
+     causes the change to be lost.
+     WAL records use a non-printable binary format.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="wal-internals"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>WAL Segment</glossterm>
+   <glosssee otherterm="glossary-wal-file" />
+  </glossentry>
+
+  <glossentry id="glossary-wal-writer">
+  <glossterm>WAL Writer (process)</glossterm>
+  <glossdef>
+   <para>
+    A process that writes <glossterm linkend="glossary-wal-record">WAL records</glossterm>
+    from <glossterm id="linkend-shared-memory">shared memory</glossterm> to
+    <glossterm id="linkend-wal-file">WAL files</glossterm>.
+   </para>
+   <para>
+    For more information, see
+    <xref linkend="runtime-config-wal"/>.
+   </para>
+  </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-window-frame">
+   <glossterm>Window frame</glossterm>
+    <glossdef>
+     <para>
+      In a result set, a subset of neighboring rows that match some user
+      specified criteria form a window frame.
+      For example, in a query that returns employees across several departments,
+      the employees from each specific department can form one window frame.
+     </para>
+    </glossdef>
+   </glossentry>
+
+  <glossentry id="glossary-window-function">
+   <glossterm>Window Function</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm linkend="glossary-function">function</glossterm> whose
+     result is based on values found in
+     <glossterm linkend="glossary-tuple">rows</glossterm> of the same
+     <glossterm linkend="glossary-window-frame">window frame</glossterm>.
+     All <glossterm linkend="glossary-aggregate">aggregate functions</glossterm>
+     can be used as window functions, but window functions can also be
+     used to, for example, give ranks to each of the rows in the window frame.
+     Also known as <firstterm>analytic functions</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="tutorial-window"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal">
+   <glossterm>Write-Ahead Log</glossterm>
+   <glossdef>
+    <para>
+     The journal that keeps track of the changes in the
+     <glossterm>Instance</glossterm> as user- and system-invoked
+     operations take place.  It comprises many individual
+     <glossterm linkend="glossary-wal-record">WAL records</glossterm> written
+     sequentially to <glossterm linkend="glossary-wal-file">WAL files</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+ </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 1f7bd32878..ba3d626102 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
   &docguide;
   &limits;
   &acronyms;
+  &glossary;
   &color;
 
  </part>

diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 1043d0f7ab..cf21ef857e 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..fb4934d322
--- /dev/null
+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,1580 @@
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+  This is a list of terms and their meaning in the context of
+  <productname>PostgreSQL</productname> and relational database
+  systems in general.
+ </para>
+
+ <glosslist>
+  <glossentry id="glossary-aggregate">
+   <glossterm>Aggregate Function</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-function">function</glossterm> that
+     combines (<firstterm>aggregates</firstterm>) multiple input values,
+     for example by counting, averaging or adding,
+     yielding a single output value.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="functions-aggregate"/>.
+    </para>
+    <glossseealso otherterm="glossary-window-function" />
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-analyze">
+   <glossterm>Analyze (operation)</glossterm>
+   <glossdef>
+    <para>
+     The process of collecting statistics from data in
+     <glossterm linkend="glossary-table">tables</glossterm>
+     and other <glossterm linkend="glossary-relation">relations</glossterm>
+     to help the <glossterm linkend="glossary-planner">query planner</glossterm>
+     to make decisions about how to execute
+     <glossterm linkend="glossary-query">queries</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Analytic Function</glossterm>
+   <glosssee otherterm="glossary-window-function" />
+  </glossentry>
+
+  <glossentry id="glossary-atomic">
+   <glossterm>Atomic</glossterm>
+   <glossdef>
+    <para>
+     In reference to a <glossterm linkend="glossary-datum">datum</glossterm>:
+     the fact that its value that cannot be broken down into smaller
+     components.
+    </para>
+   </glossdef>
+   <glossdef>
+    <para>
+     In reference to a
+     <glossterm linkend="glossary-transaction">database transaction</glossterm>:
+     see <glossterm linkend="glossary-atomicity">atomicity</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-atomicity">
+   <glossterm>Atomicity</glossterm>
+   <glossdef>
+    <para>
+     The property of a <glossterm linkend="glossary-transaction">transaction</glossterm>
+     that either all its operations complete as a single unit or none do.
+     This is one of the <acronym>ACID</acronym> properties.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-attribute">
+   <glossterm>Attribute</glossterm>
+   <glossdef>
+    <para>
+     An element with a certain name and data type found within a
+     <glossterm linkend="glossary-tuple">tuple</glossterm> or
+     <glossterm linkend="glossary-table">table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-autovacuum">
+   <glossterm>Autovacuum</glossterm>
+   <glossdef>
+    <para>
+     Background processes that routinely perform
+     <glossterm>Vacuum</glossterm> and <glossterm>Analyze</glossterm>
+     operations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="routine-vacuuming"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-backend">
+   <glossterm>Backend (process)</glossterm>
+   <glossdef>
+    <para>
+     Processes of an <glossterm>Instance</glossterm> which act on behalf of
+     client <glossterm>Connection</glossterm>s and handle their requests.
+    </para>
+    <para>
+     (Don't confuse this term with the similar terms
+     <glossterm>Background Worker</glossterm> or
+     <glossterm>Background Writer</glossterm>).
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-background-worker">
+   <glossterm>Background Worker (process)</glossterm>
+   <glossdef>
+    <para>
+     Individual processes within an <glossterm>Instance</glossterm>, which
+     run system- or user-supplied code.  A typical use case is a process
+     which handles parts of an <acronym>SQL</acronym> query to take
+     advantage of parallel execution on servers with multiple
+     <acronym>CPU</acronym>s.
+   </para>
+   <para>
+    For more information, see
+    <xref linkend="bgworker"/>.
+   </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-background-writer">
+   <glossterm>Background Writer (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that continuously writes dirty pages from
+     <glossterm>Shared Memory</glossterm> to the file system.
+     It wakes up periodically, but
+     works only for a short period in order to distribute its expensive
+     <acronym>I/O</acronym> activity over time, instead of generating fewer
+     larger <acronym>I/O</acronym> peaks which could block other processes.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-resource"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-cast">
+   <glossterm>Cast</glossterm>
+   <glossdef>
+    <para>
+     A conversion of a <glossterm>Datum</glossterm> from its current data
+     type to another data type.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-catalog">
+   <glossterm>Catalog</glossterm>
+   <glossdef>
+    <para>
+     The <acronym>SQL</acronym> standard uses this term to
+     indicate what is called a <glossterm>Database</glossterm> in
+     <productname>PostgreSQL</productname>'s terminology.
+    </para>
+    <para>
+     This should not be confused with the
+     <glossterm>System Catalog</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-check-constraint">
+   <glossterm>Check Constraint</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm>Constraint</glossterm> defined on a
+     <glossterm>Relation</glossterm> which restricts the values allowed in
+     one or more <glossterm>Attribute</glossterm>s. The
+     <glossterm>Check Constraint</glossterm> can make reference to any
+     attribute in the <glossterm>Relation</glossterm>, but cannot reference
+     other <glossterm>Row</glossterm>s of the same
+     relation or other relations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-constraints"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-checkpointer">
+   <glossterm>Checkpointer (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that writes dirty pages to the file system and creates a special
+     checkpoint WAL record. This process is initiated when predefined
+     conditions are met, such as a specified amount of time has passed, or
+     a certain volume of records has been written.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-checkpoint">
+   <glossterm>Checkpoint</glossterm>
+   <glossdef>
+    <para>
+     A point in time when all older dirty pages of the
+     <glossterm>Shared Memory</glossterm>, all older <glossterm>WAL Record</glossterm>s,
+     and a special <firstterm>Checkpoint record</firstterm>
+     have been written and flushed to disk.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-checkpoint"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Class</glossterm>
+   <glosssee otherterm="glossary-relation" />
+  </glossentry>
+
+  <glossentry id="glossary-cluster">
+   <glossterm>Cluster</glossterm>
+   <glossdef>
+    <para>
+     A group of <glossterm>Database</glossterm>s plus their
+     <glossterm>Global SQL Object</glossterm>s. The
+     <glossterm>Cluster</glossterm> is managed by exactly one
+     <glossterm>Instance</glossterm>. A newly created
+     <glossterm>Cluster</glossterm> will have three
+     <glossterm>Database</glossterm>s created automatically. They are
+     <literal>template0</literal>, <literal>template1</literal>, and
+     <literal>postgres</literal>. It is expected that an application will
+     create one or more additional <glossterm>Database</glossterm>s aside
+     from these three.
+    </para>
+    <para>
+     Don't confuse the <productname>PostgreSQL</productname>-specific term
+     <glossterm>Cluster</glossterm> with the SQL command
+     <literal>CLUSTER</literal>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-column">
+   <glossterm>Column</glossterm>
+   <glossdef>
+    <para>
+     An <glossterm>Attribute</glossterm> found in a
+     <glossterm>Table</glossterm> or <glossterm>View</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-commit">
+   <glossterm>Commit</glossterm>
+   <glossdef>
+    <para>
+     The act of finalizing a <glossterm linkend="glossary-transaction">transaction</glossterm>
+     within the <glossterm>Database</glossterm>, which makes it visible to other
+     transactions and assures its
+     <glossterm linkend="glossary-durability">durability</glossterm>.
+    </para>
+   <para>
+    For more information, see
+    <xref linkend="sql-commit"/>.
+   </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-concurrency">
+   <glossterm>Concurrency</glossterm>
+   <glossdef>
+    <para>
+     The concept that multiple independent operations happen within the
+     <glossterm>Database</glossterm> at the same time.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-connection">
+   <glossterm>Connection</glossterm>
+   <glossdef>
+    <para>
+     An established line of communication between a client process
+     and a <glossterm linkend="glossary-backend">backend</glossterm>,
+     usually over a network.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-connection"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-consistency">
+   <glossterm>Consistency</glossterm>
+   <glossdef>
+    <para>
+     The property that the data in the <glossterm linkend="glossary-database">database</glossterm>
+     is always in compliance with its own rules such as <glossterm>Table</glossterm>
+     structure, <glossterm>Constraint</glossterm>s,
+     <glossterm linkend="glossary-unique">uniqueness</glossterm>, etc.
+     This is one of the <acronym>ACID</acronym> properties.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-constraint">
+   <glossterm>Constraint</glossterm>
+   <glossdef>
+    <para>
+     A restriction on the values of data allowed within a
+     <glossterm>Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-constraints"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Data Area</glossterm>
+   <glosssee otherterm="glossary-data-directory" />
+  </glossentry>
+
+  <glossentry id="glossary-data-directory">
+   <glossterm>Data Directory</glossterm>
+   <glossdef>
+    <para>
+     The base directory on the filesystem of a
+     <glossterm>Server</glossterm> that contains all data files and
+     subdirectories associated with a <glossterm>Cluster</glossterm> with
+     the exception of <glossterm>Tablespace</glossterm>s. The environment
+     variable <literal>PGDATA</literal> often &mdash; but not always &mdash;
+     refers to the <glossterm>Data Directory</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="storage-file-layout"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-database">
+   <glossterm>Database</glossterm>
+   <glossdef>
+    <para>
+     A named collection of <glossterm>SQL Object</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Database Server</glossterm>
+   <glosssee otherterm="glossary-instance" />
+  </glossentry>
+
+  <glossentry id="glossary-datum">
+   <glossterm>Datum</glossterm>
+   <glossdef>
+    <para>
+     The internal representation of one value of a <acronym>SQL</acronym>
+     data type.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-delete">
+   <glossterm>Delete</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command which removes
+     <glossterm>Row</glossterm>s from a given <glossterm>Table</glossterm>
+     or <glossterm>Relation</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-delete"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-durability">
+   <glossterm>Durability</glossterm>
+   <glossdef>
+    <para>
+     The assurance that once a <glossterm linkend="glossary-transaction">transaction</glossterm>
+     has been <glossterm>Committed</glossterm>, the changes remain even after
+     a system failure or crash.
+     This is one of the <acronym>ACID</acronym> properties. 
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-file-segment">
+   <glossterm>File Segment</glossterm>
+   <glossdef>
+    <para>
+     A physical file which stores data for a given
+     <glossterm>Heap</glossterm> or <glossterm>Index</glossterm> object.
+     <glossterm>File Segment</glossterm>s are limited in size by a
+     configuration value and if that size is exceeded, it will be split
+     into multiple physical files.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="storage-file-layout"/>.
+    </para>
+    <para>
+     (Don't confuse this term with the similar term
+     <glossterm>WAL Segment</glossterm>).
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-data-wrapper">
+   <glossterm>Foreign Data Wrapper</glossterm>
+   <glossdef>
+    <para>
+     A means of representing data that is not contained in the local
+     <glossterm>Database</glossterm> so that it appears as if were in local
+     <glossterm>Table</glossterm>(s). With a Foreign Data Wrapper it is
+     possible to define a <glossterm>Foreign Server</glossterm> and
+     <glossterm>Foreign Table</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createforeigndatawrapper"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-key">
+   <glossterm>Foreign Key</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm>Constraint</glossterm> defined on one or more
+     <glossterm>Column</glossterm>s in a <glossterm>Table</glossterm> which
+     requires the value(s) in those <glossterm>Column</glossterm>s to
+     identify exactly one <glossterm>Row</glossterm> in another (or the same)
+     <glossterm>Table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-server">
+   <glossterm>Foreign Server</glossterm>
+   <glossdef>
+    <para>
+     A named collection of <glossterm>Foreign Table</glossterm>s which all
+     use the same <glossterm>Foreign Data Wrapper</glossterm> and have
+     other configuration values in common.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createserver"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-table">
+   <glossterm>Foreign Table</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Relation</glossterm> which appears to have
+     <glossterm>Row</glossterm>s and <glossterm>Column</glossterm>s similar
+     to a regular <glossterm>Table</glossterm>, but will forward requests
+     for data through its <glossterm>Foreign Data Wrapper</glossterm>,
+     which will return <glossterm>Result Set</glossterm>s structured
+     according to the definition of the <glossterm>Foreign Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createforeigntable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-function">
+   <glossterm>Function</glossterm>
+   <glossdef>
+    <para>
+     Any defined transformation of data. Many functions are already defined
+     within <productname>PostgreSQL</productname> itself, but user-defined
+     ones can also be added.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createfunction"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-global-sql-object">
+   <glossterm>Global SQL Object</glossterm>
+   <glossdef>
+    <para>
+     <glossterm>SQL Object</glossterm>s which do not belong to a specific
+     <glossterm>Schema</glossterm>.
+    </para>
+    <para>
+     Objects that exist at the <glossterm>Database</glossterm> level
+     include Extensions such as
+     <glossterm>Foreign Data Wrapper</glossterm>s.
+    </para>
+    <para>
+     Objects that exist at the <glossterm>Cluster</glossterm> level
+     include <glossterm>Role</glossterm>s,
+     <glossterm>Tablespace</glossterm>s,
+     <glossterm>Replication</glossterm> origins, and subscriptions
+     for logical replication.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-grant">
+   <glossterm>Grant</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command that is used to allow
+     <glossterm>User</glossterm>s or <glossterm>Role</glossterm>s to access
+     specific objects within the <glossterm>Database</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-grant"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-heap">
+   <glossterm>Heap</glossterm>
+   <glossdef>
+    <para>
+     Contains the values of <glossterm>Row</glossterm> attributes
+     (i.e. the data). The <glossterm>Heap</glossterm> is realized within
+     <glossterm>Database</glossterm> files.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Host</glossterm>
+   <glosssee otherterm="glossary-server" />
+  </glossentry>
+
+  <glossentry id="glossary-index">
+   <glossterm>Index</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Relation</glossterm> that contains data derived from a
+     <glossterm>Table</glossterm> (or <glossterm>Relation</glossterm> types
+     such as a <glossterm>Materialized View</glossterm>). Its internal
+     structure supports fast retrieval of and access to the original
+     data.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createindex"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-insert">
+   <glossterm>Insert</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command used to add new data into a
+     <glossterm>Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-insert"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-instance">
+   <glossterm>Instance</glossterm>
+   <glossdef>
+    <para>
+     An <glossterm>Instance</glossterm> is a group of processes plus their
+     common <glossterm>Shared Memory</glossterm> running on a single
+     <glossterm>Server</glossterm>. The <glossterm>Instance</glossterm>
+     handles all key features of a <acronym>DBMS</acronym>: read and write
+     access to files and shared memory, assurance of
+     the <acronym>ACID</acronym> paradigm, <acronym>MVCC</acronym>,
+     <glossterm>Connection</glossterm>s to client programs, backup,
+     recovery, replication, privileges, etc.
+    </para>
+    <para>
+     An <glossterm>Instance</glossterm> manages exactly one
+     <glossterm>Cluster</glossterm>.
+    </para>
+    <para>
+     Many <glossterm>Instance</glossterm>s can run on the same server as
+     long as their <acronym>TCP/IP</acronym> ports do not conflict.
+     Different instances on a server may use the
+     same or different versions of <productname>PostgreSQL</productname>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-isolation">
+   <glossterm>Isolation</glossterm>
+   <glossdef>
+    <para>
+     The property that the effects of a transaction are not visible to
+     <glossterm linkend="glossary-concurrency">concurrent transactions</glossterm>
+     before it commits.
+     This is one of the <acronym>ACID</acronym> properties.
+    </para>
+    <para>
+     For more information, see <xref linkend="transaction-iso" />.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-join">
+   <glossterm>Join</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> keyword used in <command>SELECT</command> statements for
+     combining data from multiple <glossterm>Relation</glossterm>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-key">
+   <glossterm>Key</glossterm>
+   <glossdef>
+    <para>
+     A means of identifying a <glossterm>Row</glossterm> within a
+     <glossterm>Table</glossterm> or <glossterm>Relation</glossterm> by
+     values contained within one or more <glossterm>Attribute</glossterm>s
+     in that <glossterm>Table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-lock">
+   <glossterm>Lock</glossterm>
+   <glossdef>
+    <para>
+     A mechanism that allows a process to limit or prevent simultaneous
+     access to a resource.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-log-file">
+   <glossterm>Log File</glossterm>
+   <glossdef>
+    <para>
+     <glossterm>Log File</glossterm>s contain human-readable text lines about
+     events. Examples include login failures, long-running queries, etc.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="logfile-maintenance"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-logger">
+   <glossterm>Logger (process)</glossterm>
+   <glossdef>
+    <para>
+     If activated, the
+     <glossterm>Logger</glossterm> process
+     writes information about database events into the current
+     <glossterm>Log File</glossterm>. When reaching certain time- or
+     volume-dependent criteria, a new log file is created.
+     Also called <firstterm>syslogger</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-logging"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-log-record">
+   <glossterm>Log Record</glossterm>
+    <glossdef>
+     <para>
+      Archaic term for a <glossterm>WAL Record</glossterm>.
+     </para>
+    </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-logged">
+   <glossterm>Logged</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Table</glossterm> is considered
+     <glossterm>Logged</glossterm> if changes to it are sent to the
+     <glossterm>WAL Log</glossterm>. By default, all regular
+     <glossterm>Table</glossterm>s are <glossterm>Logged</glossterm>. A
+     table can be specified as <glossterm>Unlogged</glossterm> either at
+     creation time or via the <command>ALTER TABLE</command> command.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Master (server)</glossterm>
+   <glosssee otherterm="glossary-primary-server" />
+  </glossentry>
+
+  <glossentry id="glossary-materialized">
+   <glossterm>Materialized</glossterm>
+   <glossdef>
+    <para>
+     The act of storing information rather than just the method of accessing
+     the information. This term is used in <glossterm>Materialized
+     View</glossterm>s, meaning that the data derived from the
+     <glossterm>View</glossterm> is actually stored on disk separately from
+     the sources of that data. When using the term
+     <glossterm>Materialized</glossterm> to refer to
+     multi-step queries, it means that the data of a given step is stored
+     in memory, but that storage may spill over onto disk.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-materialized-view">
+   <glossterm>Materialized View</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Relation</glossterm> that is defined in the same way that
+     a <glossterm>View</glossterm> is, but stores data in the same way
+     that a <glossterm>Table</glossterm> does. It cannot be modified via
+     <command>INSERT</command>, <command>UPDATE</command>, or
+     <command>DELETE</command> operations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-creatematerializedview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-null">
+   <glossterm>Null</glossterm>
+   <glossdef>
+    <para>
+     A concept of non-existence that is a central tenet of Relational
+     Database Theory. It represents the absence of value.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Optimizer</glossterm>
+   <glosssee otherterm="glossary-planner" />
+  </glossentry>
+
+  <glossentry id="glossary-partition">
+   <glossterm>Partition</glossterm>
+   <glossdef>
+    <para>
+     In reference to a <glossterm>Table</glossterm>:
+     A <glossterm>Table</glossterm> that can be queried directly,
+     or via a partitioned table, which is a collection of
+     sub-tables, each capable of holding one defined
+     subset of information that does not overlap with any other
+     table in the collection.
+    </para>
+    <para>
+     In reference to a <glossterm>Analytic Function</glossterm>:
+     a partition is a definition that identifies which neighboring
+     <glossterm>Row</glossterm>s can be considered by the
+     function.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-postmaster">
+   <glossterm>Postmaster (process)</glossterm>
+   <glossdef>
+    <para>
+      The very first process of an <glossterm>Instance</glossterm>. It
+      starts and manages the other auxiliary processes and creates
+      <glossterm linkend="glossary-backend">backend processes</glossterm>
+      on demand.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="server-start"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-primary-server">
+   <glossterm>Primary (server)</glossterm>
+   <glossdef>
+    <para>
+     When two or more <glossterm>Database</glossterm>s are linked via
+     <glossterm>Replication</glossterm>, the <glossterm>Server</glossterm>
+     that is considered the authoritative source of information is called
+     the <firstterm>Primary</firstterm>,
+     also known as a <firstterm>master</firstterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-primary-key">
+   <glossterm>Primary Key</glossterm>
+   <glossdef>
+    <para>
+     A special case of a <glossterm>Unique Index</glossterm> defined on a
+     <glossterm>Table</glossterm> or other <glossterm>Relation</glossterm>
+     that also guarantees that all of the <glossterm>Attribute</glossterm>s
+     within the <glossterm>Primary Key</glossterm> do not have
+     <glossterm>Null</glossterm> values.  As the name implies, there can be
+     only one <glossterm>Primary Key</glossterm> per
+     table, though it is possible to have multiple
+     unique indexes that also have no null-capable attributes.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-procedure">
+   <glossterm>Procedure</glossterm>
+   <glossdef>
+    <para>
+     A defined set of instructions for manipulating data within a
+     <glossterm>Database</glossterm>. A <glossterm>Procedure</glossterm> can
+     be written in a variety of programming languages. They may seem
+     similar to <glossterm>Function</glossterm>s, but are different in that
+     they must be invoked via the <command>CALL</command> command rather
+     than the <command>SELECT</command> or <command>PERFORM</command>
+     commands, and they are allowed to make transactional statements such
+     as <command>COMMIT</command> and <command>ROLLBACK</command>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createprocedure"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-query">
+   <glossterm>Query</glossterm>
+   <glossdef>
+    <para>
+     A request sent by a client to a <glossterm linkend="glossary-backend">backend</glossterm>,
+     usually to return results or to modify data on the database.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-planner">
+   <glossterm>Query Planner</glossterm>
+   <glossdef>
+    <para>
+     The part of <productname>PostgreSQL</productname> that is devoted to
+     determining (<firstterm>planning</firstterm>) the most efficient way to
+     execute <glossterm linkend="glossary-query">queries</glossterm>.
+     Also known as <firstterm>query optimizer</firstterm>,
+     <firstterm>optimizer</firstterm>, or simply <firstterm>planner</firstterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Record</glossterm>
+   <glosssee otherterm="glossary-tuple" />
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Recycling</glossterm>
+   <glosssee otherterm="glossary-wal-file" />
+  </glossentry>
+
+  <glossentry id="glossary-referential-integrity">
+   <glossterm>Referential Integrity</glossterm>
+   <glossdef>
+    <para>
+     A means of restricting data in one <glossterm>Relation</glossterm>
+     by a <glossterm>Foreign Key</glossterm>
+     so that it must have matching data in another
+     <glossterm>Relation</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-relation">
+   <glossterm>Relation</glossterm>
+   <glossdef>
+    <para>
+     The generic term for all objects in a <glossterm>Database</glossterm>
+     that have a name and a list of <glossterm>Attribute</glossterm>s
+     defined in a specific order. <glossterm>Table</glossterm>s,
+     <glossterm>View</glossterm>s, <glossterm>Foreign Table</glossterm>s,
+     <glossterm>Materialized View</glossterm>s, and
+     <glossterm>Index</glossterm>es are all relations.
+    </para>
+    <para>
+     <firstterm>Class</firstterm> is an archaic synonym for
+     <firstterm>relation</firstterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-replica">
+   <glossterm>Replica</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Database</glossterm> that is paired with a
+     <glossterm linkend="glossary-primary-server">primary</glossterm>
+     database and is maintaining a copy of some or
+     all of the primary <glossterm>Database</glossterm>'s data. The foremost
+     reasons for doing this are to allow for greater access to that data,
+     and to maintain availability of the data in the event that the
+     <glossterm>primary</glossterm> becomes unavailable.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-replication">
+   <glossterm>Replication</glossterm>
+   <glossdef>
+    <para>
+     The act of reproducing data on one <glossterm>Server</glossterm> onto
+     another server called a <glossterm>Replica</glossterm>. This can take the
+     form of <firstterm>physical replication</firstterm>, where all file
+     changes from one server are copied verbatim,
+     or <firstterm>logical replication</firstterm> where a defined subset
+     of data changes are conveyed using a higher-level representation.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-result-set">
+   <glossterm>Result Set</glossterm>
+   <glossdef>
+    <para>
+     A data structure transmitted from a <glossterm>Backend Process</glossterm> to
+     client program upon the completion of a <acronym>SQL</acronym>
+     command, usually a <command>SELECT</command> but it can be an
+     <command>INSERT</command>, <command>UPDATE</command>, or
+     <command>DELETE</command> command if the <literal>RETURNING</literal>
+     clause is specified. The data structure consists of zero or more
+     <glossterm>Row</glossterm>s with the same ordered set of
+     <glossterm>Attribute</glossterm>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-revoke">
+   <glossterm>Revoke</glossterm>
+   <glossdef>
+    <para>
+     A command to prevent access to a named set of
+     <glossterm>Database</glossterm> objects for a named list of
+     <glossterm>User</glossterm>s and <glossterm>Role</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-revoke"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-role">
+   <glossterm>Role</glossterm>
+   <glossdef>
+    <para>
+     A collection of access privileges to the
+     <glossterm>Database</glossterm>. <glossterm>Role</glossterm>s are
+     themselves a privilege that can be granted to other roles. This is
+     often done for convenience or to ensure completeness when multiple
+     <glossterm>User</glossterm>s need the same privileges.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createrole"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-rollback">
+   <glossterm>Rollback</glossterm>
+   <glossdef>
+    <para>
+     A command to undo all of the operations performed since the beginning
+     of a <glossterm>Transaction</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-rollback"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Row</glossterm>
+   <glosssee otherterm="glossary-tuple" />
+  </glossentry>
+
+  <glossentry id="glossary-savepoint">
+   <glossterm>Savepoint</glossterm>
+   <glossdef>
+    <para>
+     A special mark inside the sequence of steps in a
+     <glossterm>Transaction</glossterm>. Data modifications after this
+     point in time may be reverted to the time of the savepoint.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-savepoint"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-schema">
+   <glossterm>Schema</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Schema</glossterm> is a namespace for
+     <glossterm>SQL object</glossterm>s, which all reside in the same
+     <glossterm>database</glossterm>.  Each
+     <glossterm>SQL object</glossterm> must reside in exactly one
+     <glossterm>Schema</glossterm>.
+    </para>
+    <para>
+     In general, the names of <glossterm>SQL Object</glossterm>s in the
+     schema are unique &mdash; even across different types of objects.  The lone
+     exception is the case of <glossterm>Unique</glossterm>
+     <glossterm>Constraint</glossterm>s, in which case there
+     <emphasis>must</emphasis> be a <glossterm>Unique Index</glossterm>
+     with the same name and <glossterm>Schema</glossterm> as the
+     <glossterm>Constraint</glossterm>.  There is no restriction on reusing
+     a name in multiple <glossterm>Schema</glossterm>s.
+    </para>
+    <para>
+     Many <glossterm>SQL Object</glossterm>s reside in the default
+     <glossterm>Schema</glossterm> <literal>public</literal>, but it is
+     expected that more schemas are created to hold application-specific
+     <glossterm>SQL Object</glossterm>s.
+    </para>
+    <para>
+     More generically, the term <glossterm>Schema</glossterm> is used to
+     mean all data descriptions (<glossterm>Table</glossterm> definitions,
+     <glossterm>Constraint</glossterm>s, comments) for a given
+     <glossterm>Database</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-schemas"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Segment</glossterm>
+   <glosssee otherterm="glossary-file-segment" />
+  </glossentry>
+
+  <glossentry id="glossary-select">
+   <glossterm>Select</glossterm>
+   <glossdef>
+    <para>
+     The <acronym>SQL</acronym> command used to query a <glossterm>Database</glossterm>.
+     Normally, <command>SELECT</command>s are not expected to modify the
+     <glossterm>Database</glossterm> in any way, but it is possible that
+     <glossterm>Function</glossterm>s invoked within the query could have
+     side effects that do modify data.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-select"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-serializable">
+   <glossterm>Serializable</glossterm>
+   <glossdef>
+    <para>
+     Transactions defined as <literal>SERIALIZABLE</literal> are unable to
+     see changes made within other transactions. In effect, for the
+     initializing session the entire <glossterm>Database</glossterm>
+     appears to be frozen for the duration of the
+     <glossterm>Transaction</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-server">
+   <glossterm>Server</glossterm>
+   <glossdef>
+    <para>
+     A computer on which <productname>PostgreSQL</productname>
+     <glossterm linkend="glossary-instance">instances</glossterm> run.
+     The term <firstterm>server</firstterm> denotes real hardware, a
+     container, or a Virtual Machine.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-session">
+   <glossterm>Session</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Connection</glossterm> to the <glossterm>Database</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-sequence">
+   <glossterm>Sequence</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Database</glossterm> object which represents the
+     mathematical concept of a numerical integral sequence. It can be
+     thought of as a <glossterm>Table</glossterm> with exactly one
+     <glossterm>Row</glossterm> and one <glossterm>Column</glossterm>. The
+     value stored is known as the current value. A
+     <glossterm>Sequence</glossterm> has a defined direction (usually
+     increasing) and an interval step (usually 1).  Whenever the
+     <literal>NEXTVAL</literal> pseudo-column of a
+     <glossterm>Sequence</glossterm> is accessed, the current value is moved
+     in the defined direction by the defined interval step, that value
+     is returned to the invoking query, and the current value of the
+     sequence is updated to reflect the new value. The value can be updated
+     multiple times in a single query, the net effect being that each row
+     selected will have a different value. Values taken from a
+     <glossterm>Sequence</glossterm> are never reverted, even in the case of
+     a <glossterm>Rollback</glossterm>, which means that the
+     <glossterm>Sequence</glossterm> will never generate the same number twice,
+     which makes it useful for generating
+     <glossterm>Primary Key</glossterm> values.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createsequence"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-shared-memory">
+   <glossterm>Shared Memory</glossterm>
+   <glossdef>
+    <para>
+     <acronym>RAM</acronym> which is used by the processes common to an
+     <glossterm>Instance</glossterm>. It mirrors parts of
+     <glossterm>Database</glossterm> files, provides an area for
+     <glossterm>WAL Record</glossterm>s, and stores additional common
+     information. Note that <glossterm>Shared Memory</glossterm> belongs to
+     the complete <glossterm>Instance</glossterm>, not to a single
+     <glossterm>Database</glossterm>.
+    </para>
+    <para>
+     <glossterm>Shared Memory</glossterm> is organized into pages. If a
+     page is modified, it is called a dirty page until it is written back
+     to the file system.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-resource-memory"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-sql-object">
+   <glossterm>SQL Object</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm>Table</glossterm>, <glossterm>View</glossterm>,
+      <glossterm>Materialized View</glossterm>,
+      <glossterm>Index</glossterm>, <glossterm>Constraint</glossterm>,
+      <glossterm>Sequence</glossterm>, <glossterm>Function</glossterm>,
+      <glossterm>Procedure</glossterm>, <glossterm>Trigger</glossterm>,
+      data type, or operator. Every <glossterm>SQL Object</glossterm>
+      belongs to exactly one <glossterm>Schema</glossterm>.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-stats-collector">
+   <glossterm>Stats Collector</glossterm>
+   <glossdef>
+    <para>
+     This process collects statistical information about the
+     <glossterm>Cluster</glossterm>'s activities.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="monitoring-stats"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-system-catalog">
+   <glossterm>System Catalog</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm>Table</glossterm>s and
+     <glossterm>View</glossterm>s which describe the structure of all
+     <acronym>SQL</acronym> objects of the <glossterm>Database</glossterm>
+     and the <glossterm>Global SQL Object</glossterm>s of the
+     <glossterm>Cluster</glossterm>. The <glossterm>System
+     Catalog</glossterm> resides in the schema
+     <literal>pg_catalog</literal>. Main parts are mirrored as
+     <glossterm>View</glossterm>s in the <glossterm>Schema</glossterm>
+     <literal>information_schema</literal>.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="ddl-schemas"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-table">
+   <glossterm>Table</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm>Tuple</glossterm>s (also known as
+     <glossterm>Row</glossterm>s or <glossterm>Record</glossterm>s) having
+     a common data structure (the same number of
+     <glossterm>Attribute</glossterm>s, in the same order, having the same
+     name and type per position). A <glossterm>Table</glossterm> is the
+     most common form of <glossterm>Relation</glossterm> in
+     <productname>PostgreSQL</productname>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-tablespace">
+   <glossterm>Tablespace</glossterm>
+   <glossdef>
+    <para>
+     A named location on the server filesystem. All <glossterm>SQL Object</glossterm>s
+     which require storage beyond their definition in the
+     <glossterm>System Catalog</glossterm>
+     must belong to a single tablespace.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-tablespaces"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-temporary-tables">
+   <glossterm>Temporary Table</glossterm>
+   <glossdef>
+    <para>
+     <glossterm>Table</glossterm>s that exist either for the lifetime of a
+     <glossterm>Session</glossterm> or a
+     <glossterm>Transaction</glossterm>, as specified at the time of creation. The
+     data in them is not visible to other sessions,
+     and is not <glossterm>Logged</glossterm>.
+     <glossterm>Temporary Table</glossterm>s are often used to store
+     intermediate data for a multi-step operation.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-transaction">
+   <glossterm>Transaction</glossterm>
+   <glossdef>
+    <para>
+     A combination of commands that must act as a single
+     <glossterm>Atomic</glossterm> command: they all succeed or all fail
+     as a single unit, and their effects are not visible to other
+     <glossterm>Session</glossterm>s until
+     the <glossterm>Transaction</glossterm> is complete.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="transaction-iso"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-trigger">
+   <glossterm>Trigger</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Function</glossterm> which can be defined to execute
+     whenever a certain operation (<command>INSERT</command>,
+     <command>UPDATE</command>, <command>DELETE</command>,
+     <command>TRUNCATE</command>) is applied to a <glossterm>Relation</glossterm>.
+     A <glossterm>Trigger</glossterm>
+     executes within the same <glossterm>Transaction</glossterm> as the
+     statement which invoked it, and if the <glossterm>Function</glossterm>
+     fails, then the invoking statement also fails.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtrigger"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-tuple">
+   <glossterm>Tuple</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm>Attribute</glossterm>s in a fixed order.
+     That order may be defined by the <glossterm>Table</glossterm> where
+     the <glossterm>Tuple</glossterm> is found, in which case the
+     <glossterm>Tuple</glossterm> is often called a
+     <glossterm>Row</glossterm> or <glossterm>Record</glossterm>. It may
+     also be defined by the structure of a
+     <glossterm>Result Set</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-unique">
+   <glossterm>Unique</glossterm>
+   <glossdef>
+    <para>
+     The condition of having no duplicate values in the same
+     <glossterm>Column</glossterm> of a <glossterm>Relation</glossterm>.
+     Often used in the concept of
+     <glossterm>Unique Index</glossterm>es.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-unlogged">
+   <glossterm>Unlogged</glossterm>
+   <glossdef>
+    <para>
+     Changes to an unlogged <glossterm>Relation</glossterm> are not
+     reflected in the <glossterm>WAL Log</glossterm>.  This disables
+     replication and crash recovery for these relations.
+    </para>
+    <para>
+     The primary use of unlogged tables is for storing
+     transient work data that must be shared across processes.
+    </para>
+    <para>
+     <glossterm>Temporary Table</glossterm>s are always unlogged.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-update">
+   <glossterm>Update</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command used to modify <glossterm>Row</glossterm>s
+     that may already exist in a specified <glossterm>Table</glossterm>.
+     It cannot create or remove rows.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-update"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-user">
+   <glossterm>User</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Role</glossterm> that has the <literal>LOGIN</literal>
+     privilege is said to be a <glossterm>User</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-user-mapping">
+   <glossterm>User Mapping</glossterm>
+   <glossdef>
+    <para>
+     The translation of login credentials in the local
+     <glossterm>Database</glossterm> to credentials in a remote data system
+     defined by a <glossterm>Foreign Data Wrapper</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createusermapping"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-vacuum">
+   <glossterm>Vacuum</glossterm>
+   <glossdef>
+    <para>
+     The process of removing outdated <acronym>MVCC</acronym>
+     <glossterm>Tuple</glossterm>s from a <glossterm>Heap</glossterm> or
+     <glossterm>Index</glossterm>. This can be initiated through the use of
+     the <command>VACUUM</command> command, but can also be handled automatically
+     via <glossterm>Autovacuum</glossterm> processes.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-vacuum"/> .
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-view">
+   <glossterm>View</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm>Relation</glossterm> that is defined by a
+     <command>SELECT</command> statement, but has no storage of its own.
+     Any time a query references a <glossterm>View</glossterm>, the
+     definition of the <glossterm>View</glossterm> is substituted into the
+     query as if the user had typed that subquery instead of the name of
+     the <glossterm>View</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal-archiver">
+   <glossterm>WAL Archiver (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that saves copies of <glossterm>WAL File</glossterm>s
+     for the purposes of creating backups or keeping
+     <glossterm>Replica</glossterm>s current.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="continuous-archiving"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal-file">
+   <glossterm>WAL File</glossterm>
+   <glossdef>
+    <para>
+     Each of the numerically-numbered files that provide storage space for
+     <glossterm linkend="glossary-wal">WAL</glossterm>.
+     The files are all of the same predefined size
+     and are written in sequential order, interspersing changes
+     as they occur in multiple simultaneous sessions.
+     If the system crashes, the files are read in order, and each of the
+     changes are replayed to restore the system to the state as it was
+     before the crash.
+    </para>
+    <para>
+     Each WAL file can be released after a
+     <glossterm linkend="glossary-checkpoint">checkpoint</glossterm>
+     writes all the changes in it to the corresponding data files.
+     Releasing the file can be done either by deleting it, or by changing its
+     name so that it will be used in the future, which is called
+     <firstterm>recycling</firstterm>.
+    </para>
+
+    <para>
+     For more information, see
+     <xref linkend="wal-internals"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>WAL</glossterm>
+   <glosssee otherterm="glossary-wal" />
+  </glossentry>
+
+  <glossentry id="glossary-wal-record">
+   <glossterm>WAL Record</glossterm>
+   <glossdef>
+    <para>
+     A low-level description of an individual data change.
+     It contains sufficient information for the data change to be
+     re-executed (<firstterm>replayed</firstterm>) in case a system failure
+     causes the change to be lost.
+     WAL records use a non-printable binary format.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="wal-internals"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>WAL Segment</glossterm>
+   <glosssee otherterm="glossary-wal-file" />
+  </glossentry>
+
+  <glossentry id="glossary-wal-writer">
+  <glossterm>WAL Writer (process)</glossterm>
+  <glossdef>
+   <para>
+    A process that writes <glossterm linkend="glossary-wal-record">WAL records</glossterm>
+    from <glossterm id="linkend-shared-memory">shared memory</glossterm> to
+    <glossterm id="linkend-wal-file">WAL files</glossterm>.
+   </para>
+   <para>
+    For more information, see
+    <xref linkend="runtime-config-wal"/>.
+   </para>
+  </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-window-frame">
+   <glossterm>Window frame</glossterm>
+    <glossdef>
+     <para>
+      In a result set, a subset of neighboring rows that match some user
+      specified criteria form a window frame.
+      For example, in a query that returns employees across several departments,
+      the employees from each specific department can form one window frame.
+     </para>
+    </glossdef>
+   </glossentry>
+
+  <glossentry id="glossary-window-function">
+   <glossterm>Window Function</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm linkend="glossary-function">function</glossterm> whose
+     result is based on values found in
+     <glossterm linkend="glossary-tuple">rows</glossterm> of the same
+     <glossterm linkend="glossary-window-frame">window frame</glossterm>.
+     All <glossterm linkend="glossary-aggregate">aggregate functions</glossterm>
+     can be used as window functions, but window functions can also be
+     used to, for example, give ranks to each of the rows in the window frame.
+     Also known as <firstterm>analytic functions</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="tutorial-window"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal">
+   <glossterm>Write-Ahead Log</glossterm>
+   <glossdef>
+    <para>
+     The journal that keeps track of the changes in the
+     <glossterm>Instance</glossterm> as user- and system-invoked
+     operations take place.  It comprises many individual
+     <glossterm linkend="glossary-wal-record">WAL records</glossterm> written
+     sequentially to <glossterm linkend="glossary-wal-file">WAL files</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+ </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 1f7bd32878..ba3d626102 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
   &docguide;
   &limits;
   &acronyms;
+  &glossary;
   &color;
 
  </part>

From 4603ce04306e77f5508bb207b42e5dec1425e7c5 Mon Sep 17 00:00:00 2001
From: coreyhuinker <corey.huinker@gmail.com>
Date: Thu, 2 Apr 2020 15:32:43 -0400
Subject: [PATCH] glossary v7

---
 doc/src/sgml/filelist.sgml |    1 +
 doc/src/sgml/glossary.sgml | 1589 ++++++++++++++++++++++++++++++++++++
 doc/src/sgml/postgres.sgml |    1 +
 3 files changed, 1591 insertions(+)
 create mode 100644 doc/src/sgml/glossary.sgml

diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 1043d0f7ab..cf21ef857e 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..edfcf9d725
--- /dev/null
+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,1589 @@
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+  This is a list of terms and their meaning in the context of
+  <productname>PostgreSQL</productname> and relational database
+  systems in general.
+ </para>
+
+ <glosslist>
+  <glossentry id="glossary-aggregate">
+   <glossterm>Aggregate Function</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-function">function</glossterm> that
+     combines (<firstterm>aggregates</firstterm>) multiple input values,
+     for example by counting, averaging or adding,
+     yielding a single output value.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="functions-aggregate"/>.
+    </para>
+    <glossseealso otherterm="glossary-window-function" />
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-analyze">
+   <glossterm>Analyze (operation)</glossterm>
+   <glossdef>
+    <para>
+     The process of collecting statistics from data in
+     <glossterm linkend="glossary-table">tables</glossterm>
+     and other <glossterm linkend="glossary-relation">relations</glossterm>
+     to help the <glossterm linkend="glossary-planner">query planner</glossterm>
+     to make decisions about how to execute
+     <glossterm linkend="glossary-query">queries</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-analytic-function">
+   <glossterm>Analytic Function</glossterm>
+   <glosssee otherterm="glossary-window-function" />
+  </glossentry>
+
+  <glossentry id="glossary-atomic">
+   <glossterm>Atomic</glossterm>
+   <glossdef>
+    <para>
+     In reference to a <glossterm linkend="glossary-datum">datum</glossterm>:
+     the fact that its value that cannot be broken down into smaller
+     components.
+    </para>
+   </glossdef>
+   <glossdef>
+    <para>
+     In reference to a
+     <glossterm linkend="glossary-transaction">database transaction</glossterm>:
+     see <glossterm linkend="glossary-atomicity">atomicity</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-atomicity">
+   <glossterm>Atomicity</glossterm>
+   <glossdef>
+    <para>
+     The property of a <glossterm linkend="glossary-transaction">transaction</glossterm>
+     that either all its operations complete as a single unit or none do.
+     This is one of the <acronym>ACID</acronym> properties.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-attribute">
+   <glossterm>Attribute</glossterm>
+   <glossdef>
+    <para>
+     An element with a certain name and data type found within a
+     <glossterm linkend="glossary-tuple">tuple</glossterm> or
+     <glossterm linkend="glossary-table">table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-autovacuum">
+   <glossterm>Autovacuum</glossterm>
+   <glossdef>
+    <para>
+     Background processes that routinely perform
+     <glossterm linkend="glossary-vacuum">Vacuum</glossterm> and <glossterm linkend="glossary-analyze">Analyze</glossterm>
+     operations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="routine-vacuuming"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-backend">
+   <glossterm>Backend (process)</glossterm>
+   <glossdef>
+    <para>
+     Processes of an <glossterm linkend="glossary-instance">Instance</glossterm> which act on behalf of
+     client <glossterm linkend="glossary-connection">Connection</glossterm>s and handle their requests.
+    </para>
+    <para>
+     (Don't confuse this term with the similar terms
+     <glossterm linkend="glossary-background-worker">Background Worker</glossterm> or
+     <glossterm linkend="glossary-background-writer">Background Writer</glossterm>).
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-background-worker">
+   <glossterm>Background Worker (process)</glossterm>
+   <glossdef>
+    <para>
+     Individual processes within an <glossterm linkend="glossary-instance">Instance</glossterm>, which
+     run system- or user-supplied code.  A typical use case is a process
+     which handles parts of an <acronym>SQL</acronym> query to take
+     advantage of parallel execution on servers with multiple
+     <acronym>CPU</acronym>s.
+   </para>
+   <para>
+    For more information, see
+    <xref linkend="bgworker"/>.
+   </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-background-writer">
+   <glossterm>Background Writer (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that continuously writes dirty pages from
+     <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm> to the file system.
+     It wakes up periodically, but
+     works only for a short period in order to distribute its expensive
+     <acronym>I/O</acronym> activity over time, instead of generating fewer
+     larger <acronym>I/O</acronym> peaks which could block other processes.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-resource"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-cast">
+   <glossterm>Cast</glossterm>
+   <glossdef>
+    <para>
+     A conversion of a <glossterm linkend="glossary-cast">Datum</glossterm> from its current data
+     type to another data type.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-catalog">
+   <glossterm>Catalog</glossterm>
+   <glossdef>
+    <para>
+     The <acronym>SQL</acronym> standard uses this term to
+     indicate what is called a <glossterm linkend="glossary-database">Database</glossterm> in
+     <productname>PostgreSQL</productname>'s terminology.
+    </para>
+    <para>
+     This should not be confused with the
+     <glossterm linkend="glossary-system-catalog">System Catalog</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-check-constraint">
+   <glossterm>Check Constraint</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm linkend="glossary-constraint">Constraint</glossterm> defined on a
+     <glossterm linkend="glossary-relation">Relation</glossterm> which restricts the values allowed in
+     one or more <glossterm linkend="glossary-attribute">Attribute</glossterm>s. The
+     <glossterm linkend="glossary-check-constraint">Check Constraint</glossterm> can make reference to any
+     attribute in the <glossterm linkend="glossary-relation">Relation</glossterm>, but cannot reference
+     other <glossterm linkend="glossary-row">Row</glossterm>s of the same
+     relation or other relations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-constraints"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-checkpointer">
+   <glossterm>Checkpointer (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that writes dirty pages to the file system and creates a special
+     checkpoint WAL record. This process is initiated when predefined
+     conditions are met, such as a specified amount of time has passed, or
+     a certain volume of records has been written.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-checkpoint">
+   <glossterm>Checkpoint</glossterm>
+   <glossdef>
+    <para>
+     A point in time when all older dirty pages of the
+     <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm>, all older <glossterm linkend="glossary-wal-record">WAL Record</glossterm>s,
+     and a special <firstterm>Checkpoint record</firstterm>
+     have been written and flushed to disk.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-checkpoint"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Class</glossterm>
+   <glosssee otherterm="glossary-relation" />
+  </glossentry>
+
+  <glossentry id="glossary-cluster">
+   <glossterm>Cluster</glossterm>
+   <glossdef>
+    <para>
+     A group of <glossterm linkend="glossary-database">Database</glossterm>s plus their
+     <glossterm linkend="glossary-global-sql-object">Global SQL Object</glossterm>s. The
+     <glossterm linkend="glossary-cluster">Cluster</glossterm> is managed by exactly one
+     <glossterm linkend="glossary-instance">Instance</glossterm>. A newly created
+     <glossterm linkend="glossary-cluster">Cluster</glossterm> will have three
+     <glossterm linkend="glossary-database">Database</glossterm>s created automatically. They are
+     <literal>template0</literal>, <literal>template1</literal>, and
+     <literal>postgres</literal>. It is expected that an application will
+     create one or more additional <glossterm linkend="glossary-database">Database</glossterm>s aside
+     from these three.
+    </para>
+    <para>
+     Don't confuse the <productname>PostgreSQL</productname>-specific term
+     <glossterm linkend="glossary-cluster">Cluster</glossterm> with the SQL command
+     <literal>CLUSTER</literal>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-column">
+   <glossterm>Column</glossterm>
+   <glossdef>
+    <para>
+     An <glossterm linkend="glossary-attribute">Attribute</glossterm> found in a
+     <glossterm linkend="glossary-table">Table</glossterm> or <glossterm linkend="glossary-view">View</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-commit">
+   <glossterm>Commit</glossterm>
+   <glossdef>
+    <para>
+     The act of finalizing a <glossterm linkend="glossary-transaction">transaction</glossterm>
+     within the <glossterm linkend="glossary-database">Database</glossterm>, which makes it visible to other
+     transactions and assures its
+     <glossterm linkend="glossary-durability">durability</glossterm>.
+    </para>
+   <para>
+    For more information, see
+    <xref linkend="sql-commit"/>.
+   </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-concurrency">
+   <glossterm>Concurrency</glossterm>
+   <glossdef>
+    <para>
+     The concept that multiple independent operations happen within the
+     <glossterm linkend="glossary-database">Database</glossterm> at the same time.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-connection">
+   <glossterm>Connection</glossterm>
+   <glossdef>
+    <para>
+     An established line of communication between a client process
+     and a <glossterm linkend="glossary-backend">backend</glossterm>,
+     usually over a network.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-connection"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-consistency">
+   <glossterm>Consistency</glossterm>
+   <glossdef>
+    <para>
+     The property that the data in the <glossterm linkend="glossary-database">database</glossterm>
+     is always in compliance with its own rules such as <glossterm linkend="glossary-table">Table</glossterm>
+     structure, <glossterm linkend="glossary-constraint">Constraint</glossterm>s,
+     <glossterm linkend="glossary-unique">uniqueness</glossterm>, etc.
+     This is one of the <acronym>ACID</acronym> properties.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-constraint">
+   <glossterm>Constraint</glossterm>
+   <glossdef>
+    <para>
+     A restriction on the values of data allowed within a
+     <glossterm linkend="glossary-table">Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-constraints"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Data Area</glossterm>
+   <glosssee otherterm="glossary-data-directory" />
+  </glossentry>
+
+  <glossentry id="glossary-data-directory">
+   <glossterm>Data Directory</glossterm>
+   <glossdef>
+    <para>
+     The base directory on the filesystem of a
+     <glossterm linkend="glossary-server">Server</glossterm> that contains all data files and
+     subdirectories associated with a <glossterm linkend="glossary-cluster">Cluster</glossterm> with
+     the exception of <glossterm linkend="glossary-tablespace">Tablespace</glossterm>s. The environment
+     variable <literal>PGDATA</literal> often &mdash; but not always &mdash;
+     refers to the <glossterm linkend="glossary-data-directory">Data Directory</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="storage-file-layout"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-database">
+   <glossterm>Database</glossterm>
+   <glossdef>
+    <para>
+     A named collection of <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Database Server</glossterm>
+   <glosssee otherterm="glossary-instance" />
+  </glossentry>
+
+  <glossentry id="glossary-datum">
+   <glossterm>Datum</glossterm>
+   <glossdef>
+    <para>
+     The internal representation of one value of a <acronym>SQL</acronym>
+     data type.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-delete">
+   <glossterm>Delete</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command which removes
+     <glossterm linkend="glossary-row">Row</glossterm>s from a given <glossterm linkend="glossary-table">Table</glossterm>
+     or <glossterm linkend="glossary-relation">Relation</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-delete"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-durability">
+   <glossterm>Durability</glossterm>
+   <glossdef>
+    <para>
+     The assurance that once a <glossterm linkend="glossary-transaction">transaction</glossterm>
+     has been <glossterm linkend="glossary-commit">Committed</glossterm>, the changes remain even after
+     a system failure or crash.
+     This is one of the <acronym>ACID</acronym> properties. 
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-file-segment">
+   <glossterm>File Segment</glossterm>
+   <glossdef>
+    <para>
+     A physical file which stores data for a given
+     <glossterm linkend="glossary-heap">Heap</glossterm> or <glossterm linkend="glossary-index">Index</glossterm> object.
+     <glossterm linkend="glossary-file-segment">File Segment</glossterm>s are limited in size by a
+     configuration value and if that size is exceeded, it will be split
+     into multiple physical files.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="storage-file-layout"/>.
+    </para>
+    <para>
+     (Don't confuse this term with the similar term
+     <glossterm linkend="glossary-wal-segment">WAL Segment</glossterm>).
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-data-wrapper">
+   <glossterm>Foreign Data Wrapper</glossterm>
+   <glossdef>
+    <para>
+     A means of representing data that is not contained in the local
+     <glossterm linkend="glossary-database">Database</glossterm> so that it appears as if were in local
+     <glossterm linkend="glossary-table">Table</glossterm>(s). With a Foreign Data Wrapper it is
+     possible to define a <glossterm linkend="glossary-foreign-server">Foreign Server</glossterm> and
+     <glossterm linkend="glossary-foreign-table">Foreign Table</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createforeigndatawrapper"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-key">
+   <glossterm>Foreign Key</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm linkend="glossary-constraint">Constraint</glossterm> defined on one or more
+     <glossterm linkend="glossary-column">Column</glossterm>s in a <glossterm linkend="glossary-table">Table</glossterm> which
+     requires the value(s) in those <glossterm linkend="glossary-column">Column</glossterm>s to
+     identify exactly one <glossterm linkend="glossary-row">Row</glossterm> in another (or the same)
+     <glossterm linkend="glossary-table">Table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-server">
+   <glossterm>Foreign Server</glossterm>
+   <glossdef>
+    <para>
+     A named collection of <glossterm linkend="glossary-foreign-table">Foreign Table</glossterm>s which all
+     use the same <glossterm linkend="glossary-foreign-data-wrapper">Foreign Data Wrapper</glossterm> and have
+     other configuration values in common.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createserver"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-table">
+   <glossterm>Foreign Table</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-relation">Relation</glossterm> which appears to have
+     <glossterm linkend="glossary-row">Row</glossterm>s and <glossterm linkend="glossary-column">Column</glossterm>s similar
+     to a regular <glossterm linkend="glossary-table">Table</glossterm>, but will forward requests
+     for data through its <glossterm linkend="glossary-foreign-data-wrapper">Foreign Data Wrapper</glossterm>,
+     which will return <glossterm linkend="glossary-result-set">Result Set</glossterm>s structured
+     according to the definition of the <glossterm linkend="glossary-foreign-table">Foreign Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createforeigntable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-function">
+   <glossterm>Function</glossterm>
+   <glossdef>
+    <para>
+     Any defined transformation of data. Many functions are already defined
+     within <productname>PostgreSQL</productname> itself, but user-defined
+     ones can also be added.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createfunction"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-global-sql-object">
+   <glossterm>Global SQL Object</glossterm>
+   <glossdef>
+    <para>
+     <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s which do not belong to a specific
+     <glossterm linkend="glossary-schema">Schema</glossterm>.
+    </para>
+    <para>
+     Objects that exist at the <glossterm linkend="glossary-database">Database</glossterm> level
+     include Extensions such as
+     <glossterm linkend="glossary-foreign-data-wrapper">Foreign Data Wrapper</glossterm>s.
+    </para>
+    <para>
+     Objects that exist at the <glossterm linkend="glossary-cluster">Cluster</glossterm> level
+     include <glossterm linkend="glossary-role">Role</glossterm>s,
+     <glossterm linkend="glossary-tablespace">Tablespace</glossterm>s,
+     <glossterm linkend="glossary-replication">Replication</glossterm> origins, and subscriptions
+     for logical replication.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-grant">
+   <glossterm>Grant</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command that is used to allow
+     <glossterm linkend="glossary-user">User</glossterm>s or <glossterm linkend="glossary-role">Role</glossterm>s to access
+     specific objects within the <glossterm linkend="glossary-database">Database</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-grant"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-heap">
+   <glossterm>Heap</glossterm>
+   <glossdef>
+    <para>
+     Contains the values of <glossterm linkend="glossary-row">Row</glossterm> attributes
+     (i.e. the data). The <glossterm linkend="glossary-heap">Heap</glossterm> is realized within
+     <glossterm linkend="glossary-database">Database</glossterm> files.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Host</glossterm>
+   <glosssee otherterm="glossary-server" />
+  </glossentry>
+
+  <glossentry id="glossary-index">
+   <glossterm>Index</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-relation">Relation</glossterm> that contains data derived from a
+     <glossterm linkend="glossary-table">Table</glossterm> (or <glossterm linkend="glossary-relation">Relation</glossterm> types
+     such as a <glossterm linkend="glossary-materialized-view">Materialized View</glossterm>). Its internal
+     structure supports fast retrieval of and access to the original
+     data.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createindex"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-insert">
+   <glossterm>Insert</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command used to add new data into a
+     <glossterm linkend="glossary-table">Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-insert"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-instance">
+   <glossterm>Instance</glossterm>
+   <glossdef>
+    <para>
+     An <glossterm linkend="glossary-instance">Instance</glossterm> is a group of processes plus their
+     common <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm> running on a single
+     <glossterm linkend="glossary-server">Server</glossterm>. The <glossterm linkend="glossary-instance">Instance</glossterm>
+     handles all key features of a <acronym>DBMS</acronym>: read and write
+     access to files and shared memory, assurance of
+     the <acronym>ACID</acronym> paradigm, <acronym>MVCC</acronym>,
+     <glossterm linkend="glossary-connection">Connection</glossterm>s to client programs, backup,
+     recovery, replication, privileges, etc.
+    </para>
+    <para>
+     An <glossterm linkend="glossary-instance">Instance</glossterm> manages exactly one
+     <glossterm linkend="glossary-cluster">Cluster</glossterm>.
+    </para>
+    <para>
+     Many <glossterm linkend="glossary-instance">Instance</glossterm>s can run on the same server as
+     long as their <acronym>TCP/IP</acronym> ports do not conflict.
+     Different instances on a server may use the
+     same or different versions of <productname>PostgreSQL</productname>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-isolation">
+   <glossterm>Isolation</glossterm>
+   <glossdef>
+    <para>
+     The property that the effects of a transaction are not visible to
+     <glossterm linkend="glossary-concurrency">concurrent transactions</glossterm>
+     before it commits.
+     This is one of the <acronym>ACID</acronym> properties.
+    </para>
+    <para>
+     For more information, see <xref linkend="transaction-iso" />.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-join">
+   <glossterm>Join</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> keyword used in <command>SELECT</command> statements for
+     combining data from multiple <glossterm linkend="glossary-relation">Relation</glossterm>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-key">
+   <glossterm>Key</glossterm>
+   <glossdef>
+    <para>
+     A means of identifying a <glossterm linkend="glossary-row">Row</glossterm> within a
+     <glossterm linkend="glossary-table">Table</glossterm> or <glossterm linkend="glossary-relation">Relation</glossterm> by
+     values contained within one or more <glossterm linkend="glossary-attribute">Attribute</glossterm>s
+     in that <glossterm linkend="glossary-table">Table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-lock">
+   <glossterm>Lock</glossterm>
+   <glossdef>
+    <para>
+     A mechanism that allows a process to limit or prevent simultaneous
+     access to a resource.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-log-file">
+   <glossterm>Log File</glossterm>
+   <glossdef>
+    <para>
+     <glossterm>Log File</glossterm>s contain human-readable text lines about
+     events. Examples include login failures, long-running queries, etc.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="logfile-maintenance"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-logger">
+   <glossterm>Logger (process)</glossterm>
+   <glossdef>
+    <para>
+     If activated, the
+     <glossterm linkend="glossary-logger">Logger</glossterm> process
+     writes information about database events into the current
+     <glossterm linkend="glossary-log-file">Log File</glossterm>. When reaching certain time- or
+     volume-dependent criteria, a new log file is created.
+     Also called <firstterm>syslogger</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-logging"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-log-record">
+   <glossterm>Log Record</glossterm>
+    <glossdef>
+     <para>
+      Archaic term for a <glossterm linkend="glossary-wal-record">WAL Record</glossterm>.
+     </para>
+    </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-logged">
+   <glossterm>Logged</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-table">Table</glossterm> is considered
+     <glossterm linkend="glossary-logged">Logged</glossterm> if changes to it are sent to the
+     <glossterm linkend="glossary-wal">WAL Log</glossterm>. By default, all regular
+     <glossterm linkend="glossary-table">Table</glossterm>s are <glossterm linkend="glossary-logged">Logged</glossterm>. A
+     table can be specified as <glossterm linkend="glossary-unlogged">Unlogged</glossterm> either at
+     creation time or via the <command>ALTER TABLE</command> command.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Master (server)</glossterm>
+   <glosssee otherterm="glossary-primary-server" />
+  </glossentry>
+
+  <glossentry id="glossary-materialized">
+   <glossterm>Materialized</glossterm>
+   <glossdef>
+    <para>
+     The act of storing information rather than just the method of accessing
+     the information. This term is used in <glossterm linkend="glossary-materialized-view">Materialized
+     View</glossterm>s, meaning that the data derived from the
+     <glossterm linkend="glossary-view">View</glossterm> is actually stored on disk separately from
+     the sources of that data. When using the term
+     <glossterm linkend="glossary-materialized">Materialized</glossterm> to refer to
+     multi-step queries, it means that the data of a given step is stored
+     in memory, but that storage may spill over onto disk.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-materialized-view">
+   <glossterm>Materialized View</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-relation">Relation</glossterm> that is defined in the same way that
+     a <glossterm linkend="glossary-view">View</glossterm> is, but stores data in the same way
+     that a <glossterm linkend="glossary-table">Table</glossterm> does. It cannot be modified via
+     <command>INSERT</command>, <command>UPDATE</command>, or
+     <command>DELETE</command> operations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-creatematerializedview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-null">
+   <glossterm>Null</glossterm>
+   <glossdef>
+    <para>
+     A concept of non-existence that is a central tenet of Relational
+     Database Theory. It represents the absence of value.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Optimizer</glossterm>
+   <glosssee otherterm="glossary-planner" />
+  </glossentry>
+
+  <glossentry id="glossary-partition">
+   <glossterm>Partition</glossterm>
+   <glossdef>
+    <para>
+     In reference to a <glossterm linkend="glossary-table">Table</glossterm>:
+     A <glossterm linkend="glossary-table">Table</glossterm> that can be queried directly,
+     or via a partitioned table, which is a collection of
+     sub-tables, each capable of holding one defined
+     subset of information that does not overlap with any other
+     table in the collection.
+    </para>
+    <para>
+     In reference to a <glossterm linkend="glossary-analytic-function">Analytic Function</glossterm>:
+     a partition is a definition that identifies which neighboring
+     <glossterm linkend="glossary-row">Row</glossterm>s can be considered by the
+     function.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-postmaster">
+   <glossterm>Postmaster (process)</glossterm>
+   <glossdef>
+    <para>
+      The very first process of an <glossterm linkend="glossary-instance">Instance</glossterm>. It
+      starts and manages the other auxiliary processes and creates
+      <glossterm linkend="glossary-backend">backend processes</glossterm>
+      on demand.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="server-start"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-primary-server">
+   <glossterm>Primary (server)</glossterm>
+   <glossdef>
+    <para>
+     When two or more <glossterm linkend="glossary-database">Database</glossterm>s are linked via
+     <glossterm linkend="glossary-replication">Replication</glossterm>, the <glossterm linkend="glossary-server">Server</glossterm>
+     that is considered the authoritative source of information is called
+     the <firstterm>Primary</firstterm>,
+     also known as a <firstterm>master</firstterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-primary-key">
+   <glossterm>Primary Key</glossterm>
+   <glossdef>
+    <para>
+     A special case of a <glossterm linkend="glossary-unique-index">Unique Index</glossterm> defined on a
+     <glossterm linkend="glossary-table">Table</glossterm> or other <glossterm linkend="glossary-relation">Relation</glossterm>
+     that also guarantees that all of the <glossterm linkend="glossary-attribute">Attribute</glossterm>s
+     within the <glossterm linkend="glossary-primary-key">Primary Key</glossterm> do not have
+     <glossterm linkend="glossary-null">Null</glossterm> values.  As the name implies, there can be
+     only one <glossterm linkend="glossary-primary-key">Primary Key</glossterm> per
+     table, though it is possible to have multiple
+     unique indexes that also have no null-capable attributes.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-procedure">
+   <glossterm>Procedure</glossterm>
+   <glossdef>
+    <para>
+     A defined set of instructions for manipulating data within a
+     <glossterm linkend="glossary-database">Database</glossterm>. A <glossterm linkend="glossary-procedure">Procedure</glossterm> can
+     be written in a variety of programming languages. They may seem
+     similar to <glossterm linkend="glossary-function">Function</glossterm>s, but are different in that
+     they must be invoked via the <command>CALL</command> command rather
+     than the <command>SELECT</command> or <command>PERFORM</command>
+     commands, and they are allowed to make transactional statements such
+     as <command>COMMIT</command> and <command>ROLLBACK</command>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createprocedure"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-query">
+   <glossterm>Query</glossterm>
+   <glossdef>
+    <para>
+     A request sent by a client to a <glossterm linkend="glossary-backend">backend</glossterm>,
+     usually to return results or to modify data on the database.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-planner">
+   <glossterm>Query Planner</glossterm>
+   <glossdef>
+    <para>
+     The part of <productname>PostgreSQL</productname> that is devoted to
+     determining (<firstterm>planning</firstterm>) the most efficient way to
+     execute <glossterm linkend="glossary-query">queries</glossterm>.
+     Also known as <firstterm>query optimizer</firstterm>,
+     <firstterm>optimizer</firstterm>, or simply <firstterm>planner</firstterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-record">
+   <glossterm>Record</glossterm>
+   <glosssee otherterm="glossary-tuple" />
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Recycling</glossterm>
+   <glosssee otherterm="glossary-wal-file" />
+  </glossentry>
+
+  <glossentry id="glossary-referential-integrity">
+   <glossterm>Referential Integrity</glossterm>
+   <glossdef>
+    <para>
+     A means of restricting data in one <glossterm linkend="glossary-relation">Relation</glossterm>
+     by a <glossterm linkend="glossary-foreign-key">Foreign Key</glossterm>
+     so that it must have matching data in another
+     <glossterm linkend="glossary-relation">Relation</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-relation">
+   <glossterm>Relation</glossterm>
+   <glossdef>
+    <para>
+     The generic term for all objects in a <glossterm linkend="glossary-database">Database</glossterm>
+     that have a name and a list of <glossterm linkend="glossary-attribute">Attribute</glossterm>s
+     defined in a specific order. <glossterm linkend="glossary-table">Table</glossterm>s,
+     <glossterm linkend="glossary-view">View</glossterm>s, <glossterm linkend="glossary-foreign-table">Foreign Table</glossterm>s,
+     <glossterm linkend="glossary-materialized-view">Materialized View</glossterm>s, and
+     <glossterm linkend="glossary-index">Index</glossterm>es are all relations.
+    </para>
+    <para>
+     <firstterm>Class</firstterm> is an archaic synonym for
+     <firstterm>relation</firstterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-replica">
+   <glossterm>Replica</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-database">Database</glossterm> that is paired with a
+     <glossterm linkend="glossary-primary-server">primary</glossterm>
+     database and is maintaining a copy of some or
+     all of the primary <glossterm linkend="glossary-database">Database</glossterm>'s data. The foremost
+     reasons for doing this are to allow for greater access to that data,
+     and to maintain availability of the data in the event that the
+     <glossterm linkend="glossary-primary-server">primary</glossterm> becomes unavailable.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-replication">
+   <glossterm>Replication</glossterm>
+   <glossdef>
+    <para>
+     The act of reproducing data on one <glossterm linkend="glossary-server">Server</glossterm> onto
+     another server called a <glossterm linkend="glossary-replica">Replica</glossterm>. This can take the
+     form of <firstterm>physical replication</firstterm>, where all file
+     changes from one server are copied verbatim,
+     or <firstterm>logical replication</firstterm> where a defined subset
+     of data changes are conveyed using a higher-level representation.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-result-set">
+   <glossterm>Result Set</glossterm>
+   <glossdef>
+    <para>
+     A data structure transmitted from a <glossterm linkend="glossary-backend">Backend Process</glossterm> to
+     client program upon the completion of a <acronym>SQL</acronym>
+     command, usually a <command>SELECT</command> but it can be an
+     <command>INSERT</command>, <command>UPDATE</command>, or
+     <command>DELETE</command> command if the <literal>RETURNING</literal>
+     clause is specified. The data structure consists of zero or more
+     <glossterm linkend="glossary-row">Row</glossterm>s with the same ordered set of
+     <glossterm linkend="glossary-attribute">Attribute</glossterm>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-revoke">
+   <glossterm>Revoke</glossterm>
+   <glossdef>
+    <para>
+     A command to prevent access to a named set of
+     <glossterm linkend="glossary-database">Database</glossterm> objects for a named list of
+     <glossterm linkend="glossary-user">User</glossterm>s and <glossterm linkend="glossary-role">Role</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-revoke"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-role">
+   <glossterm>Role</glossterm>
+   <glossdef>
+    <para>
+     A collection of access privileges to the
+     <glossterm linkend="glossary-database">Database</glossterm>. <glossterm linkend="glossary-role">Role</glossterm>s are
+     themselves a privilege that can be granted to other roles. This is
+     often done for convenience or to ensure completeness when multiple
+     <glossterm linkend="glossary-user">User</glossterm>s need the same privileges.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createrole"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-rollback">
+   <glossterm>Rollback</glossterm>
+   <glossdef>
+    <para>
+     A command to undo all of the operations performed since the beginning
+     of a <glossterm linkend="glossary-transaction">Transaction</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-rollback"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-row">
+   <glossterm>Row</glossterm>
+   <glosssee otherterm="glossary-tuple" />
+  </glossentry>
+
+  <glossentry id="glossary-savepoint">
+   <glossterm>Savepoint</glossterm>
+   <glossdef>
+    <para>
+     A special mark inside the sequence of steps in a
+     <glossterm linkend="glossary-transaction">Transaction</glossterm>. Data modifications after this
+     point in time may be reverted to the time of the savepoint.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-savepoint"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-schema">
+   <glossterm>Schema</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-schema">Schema</glossterm> is a namespace for
+     <glossterm linkend="glossary-sql-object">SQL object</glossterm>s, which all reside in the same
+     <glossterm linkend="glossary-database">database</glossterm>.  Each
+     <glossterm linkend="glossary-sql-object">SQL object</glossterm> must reside in exactly one
+     <glossterm linkend="glossary-schema">Schema</glossterm>.
+    </para>
+    <para>
+     In general, the names of <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s in the
+     schema are unique &mdash; even across different types of objects.  The lone
+     exception is the case of <glossterm linkend="glossary-unique">Unique</glossterm>
+     <glossterm linkend="glossary-constraint">Constraint</glossterm>s, in which case there
+     <emphasis>must</emphasis> be a <glossterm linkend="glossary-unique-index">Unique Index</glossterm>
+     with the same name and <glossterm linkend="glossary-schema">Schema</glossterm> as the
+     <glossterm linkend="glossary-constraint">Constraint</glossterm>.  There is no restriction on reusing
+     a name in multiple <glossterm linkend="glossary-schema">Schema</glossterm>s.
+    </para>
+    <para>
+     Many <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s reside in the default
+     <glossterm linkend="glossary-schema">Schema</glossterm> <literal>public</literal>, but it is
+     expected that more schemas are created to hold application-specific
+     <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s.
+    </para>
+    <para>
+     More generically, the term <glossterm linkend="glossary-schema">Schema</glossterm> is used to
+     mean all data descriptions (<glossterm linkend="glossary-table">Table</glossterm> definitions,
+     <glossterm linkend="glossary-constraint">Constraint</glossterm>s, comments) for a given
+     <glossterm linkend="glossary-database">Database</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-schemas"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-segment">
+   <glossterm linkend="glossary-segment">Segment</glossterm>
+   <glosssee otherterm="glossary-file-segment" />
+  </glossentry>
+
+  <glossentry id="glossary-select">
+   <glossterm>Select</glossterm>
+   <glossdef>
+    <para>
+     The <acronym>SQL</acronym> command used to query a <glossterm linkend="glossary-database">Database</glossterm>.
+     Normally, <command>SELECT</command>s are not expected to modify the
+     <glossterm linkend="glossary-database">Database</glossterm> in any way, but it is possible that
+     <glossterm linkend="glossary-function">Function</glossterm>s invoked within the query could have
+     side effects that do modify data.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-select"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-serializable">
+   <glossterm>Serializable</glossterm>
+   <glossdef>
+    <para>
+     Transactions defined as <literal>SERIALIZABLE</literal> are unable to
+     see changes made within other transactions. In effect, for the
+     initializing session the entire <glossterm linkend="glossary-database">Database</glossterm>
+     appears to be frozen for the duration of the
+     <glossterm linkend="glossary-transaction">Transaction</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-server">
+   <glossterm>Server</glossterm>
+   <glossdef>
+    <para>
+     A computer on which <productname>PostgreSQL</productname>
+     <glossterm linkend="glossary-instance">instances</glossterm> run.
+     The term <firstterm>server</firstterm> denotes real hardware, a
+     container, or a Virtual Machine.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-session">
+    <glossterm>Session</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-connection">Connection</glossterm> to the <glossterm linkend="glossary-database">Database</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-sequence">
+    <glossterm>Sequence</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-database">Database</glossterm> object which represents the
+     mathematical concept of a numerical integral sequence. It can be
+     thought of as a <glossterm linkend="glossary-table">Table</glossterm> with exactly one
+     <glossterm linkend="glossary-row">Row</glossterm> and one <glossterm linkend="glossary-column">Column</glossterm>. The
+     value stored is known as the current value. A
+     <glossterm linkend="glossary-sequence">Sequence</glossterm> has a defined direction (usually
+     increasing) and an interval step (usually 1).  Whenever the
+     <literal>NEXTVAL</literal> pseudo-column of a
+     <glossterm linkend="glossary-sequence">Sequence</glossterm> is accessed, the current value is moved
+     in the defined direction by the defined interval step, that value
+     is returned to the invoking query, and the current value of the
+     sequence is updated to reflect the new value. The value can be updated
+     multiple times in a single query, the net effect being that each row
+     selected will have a different value. Values taken from a
+     <glossterm linkend="glossary-sequence">Sequence</glossterm> are never reverted, even in the case of
+     a <glossterm linkend="glossary-rollback">Rollback</glossterm>, which means that the
+     <glossterm linkend="glossary-sequence">Sequence</glossterm> will never generate the same number twice,
+     which makes it useful for generating
+     <glossterm linkend="glossary-primary-key">Primary Key</glossterm> values.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createsequence"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-shared-memory">
+    <glossterm>Shared Memory</glossterm>
+   <glossdef>
+    <para>
+     <acronym>RAM</acronym> which is used by the processes common to an
+     <glossterm linkend="glossary-instance">Instance</glossterm>. It mirrors parts of
+     <glossterm linkend="glossary-database">Database</glossterm> files, provides an area for
+     <glossterm linkend="glossary-wal-record">WAL Record</glossterm>s, and stores additional common
+     information. Note that <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm> belongs to
+     the complete <glossterm linkend="glossary-instance">Instance</glossterm>, not to a single
+     <glossterm linkend="glossary-database">Database</glossterm>.
+    </para>
+    <para>
+     <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm> is organized into pages. If a
+     page is modified, it is called a dirty page until it is written back
+     to the file system.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-resource-memory"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-sql-object">
+    <glossterm>SQL Object</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm linkend="glossary-table">Table</glossterm>, <glossterm linkend="glossary-view">View</glossterm>,
+      <glossterm linkend="glossary-materialized-view">Materialized View</glossterm>,
+      <glossterm linkend="glossary-index">Index</glossterm>, <glossterm linkend="glossary-constraint">Constraint</glossterm>,
+      <glossterm linkend="glossary-sequence">Sequence</glossterm>, <glossterm linkend="glossary-function">Function</glossterm>,
+      <glossterm linkend="glossary-procedure">Procedure</glossterm>, <glossterm linkend="glossary-trigger">Trigger</glossterm>,
+      data type, or operator. Every <glossterm linkend="glossary-sql-object">SQL Object</glossterm>
+      belongs to exactly one <glossterm linkend="glossary-schema">Schema</glossterm>.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-stats-collector">
+    <glossterm>Stats Collector</glossterm>
+   <glossdef>
+    <para>
+     This process collects statistical information about the
+     <glossterm linkend="glossary-cluster">Cluster</glossterm>'s activities.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="monitoring-stats"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-system-catalog">
+    <glossterm>System Catalog</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm linkend="glossary-table">Table</glossterm>s and
+     <glossterm linkend="glossary-view">View</glossterm>s which describe the structure of all
+     <acronym>SQL</acronym> objects of the <glossterm linkend="glossary-database">Database</glossterm>
+     and the <glossterm linkend="glossary-global-sql-object">Global SQL Object</glossterm>s of the
+     <glossterm linkend="glossary-cluster">Cluster</glossterm>. The <glossterm linkend="glossary-system-catalog">System
+     Catalog</glossterm> resides in the schema
+     <literal>pg_catalog</literal>. Main parts are mirrored as
+     <glossterm linkend="glossary-view">View</glossterm>s in the <glossterm linkend="glossary-schema">Schema</glossterm>
+     <literal>information_schema</literal>.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="ddl-schemas"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-table">
+    <glossterm>Table</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm linkend="glossary-tuple">Tuple</glossterm>s (also known as
+     <glossterm linkend="glossary-row">Row</glossterm>s or <glossterm linkend="glossary-record">Record</glossterm>s) having
+     a common data structure (the same number of
+     <glossterm linkend="glossary-attribute">Attribute</glossterm>s, in the same order, having the same
+     name and type per position). A <glossterm linkend="glossary-table">Table</glossterm> is the
+     most common form of <glossterm linkend="glossary-relation">Relation</glossterm> in
+     <productname>PostgreSQL</productname>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-tablespace">
+    <glossterm>Tablespace</glossterm>
+   <glossdef>
+    <para>
+     A named location on the server filesystem. All <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s
+     which require storage beyond their definition in the
+     <glossterm linkend="glossary-system-catalog">System Catalog</glossterm>
+     must belong to a single tablespace.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-tablespaces"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-temporary-table">
+    <glossterm>Temporary Table</glossterm>
+   <glossdef>
+    <para>
+     <glossterm linkend="glossary-table">Table</glossterm>s that exist either for the lifetime of a
+     <glossterm linkend="glossary-session">Session</glossterm> or a
+     <glossterm linkend="glossary-transaction">Transaction</glossterm>, as specified at the time of creation. The
+     data in them is not visible to other sessions,
+     and is not <glossterm linkend="glossary-logged">Logged</glossterm>.
+     <glossterm linkend="glossary-temporary-table">Temporary Table</glossterm>s are often used to store
+     intermediate data for a multi-step operation.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-transaction">
+    <glossterm>Transaction</glossterm>
+   <glossdef>
+    <para>
+     A combination of commands that must act as a single
+     <glossterm linkend="glossary-atomic">Atomic</glossterm> command: they all succeed or all fail
+     as a single unit, and their effects are not visible to other
+     <glossterm linkend="glossary-session">Session</glossterm>s until
+     the <glossterm linkend="glossary-transaction">Transaction</glossterm> is complete.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="transaction-iso"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-trigger">
+    <glossterm>Trigger</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-function">Function</glossterm> which can be defined to execute
+     whenever a certain operation (<command>INSERT</command>,
+     <command>UPDATE</command>, <command>DELETE</command>,
+     <command>TRUNCATE</command>) is applied to a <glossterm linkend="glossary-relation">Relation</glossterm>.
+     A <glossterm linkend="glossary-trigger">Trigger</glossterm>
+     executes within the same <glossterm linkend="glossary-transaction">Transaction</glossterm> as the
+     statement which invoked it, and if the <glossterm linkend="glossary-function">Function</glossterm>
+     fails, then the invoking statement also fails.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtrigger"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-tuple">
+    <glossterm>Tuple</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm linkend="glossary-attribute">Attribute</glossterm>s in a fixed order.
+     That order may be defined by the <glossterm linkend="glossary-table">Table</glossterm> where
+     the <glossterm linkend="glossary-tuple">Tuple</glossterm> is found, in which case the
+     <glossterm linkend="glossary-tuple">Tuple</glossterm> is often called a
+     <glossterm linkend="glossary-row">Row</glossterm> or <glossterm linkend="glossary-record">Record</glossterm>. It may
+     also be defined by the structure of a
+     <glossterm linkend="glossary-result-set">Result Set</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-unique">
+    <glossterm>Unique</glossterm>
+   <glossdef>
+    <para>
+     The condition of having no duplicate values in the same
+     <glossterm linkend="glossary-column">Column</glossterm> of a <glossterm linkend="glossary-relation">Relation</glossterm>.
+     Often used in the concept of
+     <glossterm linkend="glossary-unique-index">Unique Index</glossterm>es.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-unlogged">
+    <glossterm>Unlogged</glossterm>
+   <glossdef>
+    <para>
+     Changes to an unlogged <glossterm linkend="glossary-relation">Relation</glossterm> are not
+     reflected in the <glossterm linkend="glossary-wal">WAL Log</glossterm>.  This disables
+     replication and crash recovery for these relations.
+    </para>
+    <para>
+     The primary use of unlogged tables is for storing
+     transient work data that must be shared across processes.
+    </para>
+    <para>
+     <glossterm linkend="glossary-temporary-table">Temporary Table</glossterm>s are always unlogged.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-update">
+    <glossterm>Update</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command used to modify <glossterm linkend="glossary-row">Row</glossterm>s
+     that may already exist in a specified <glossterm linkend="glossary-table">Table</glossterm>.
+     It cannot create or remove rows.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-update"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-user">
+    <glossterm>User</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-role">Role</glossterm> that has the <literal>LOGIN</literal>
+     privilege is said to be a <glossterm linkend="glossary-user">User</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-user-mapping">
+    <glossterm>User Mapping</glossterm>
+   <glossdef>
+    <para>
+     The translation of login credentials in the local
+     <glossterm linkend="glossary-database">Database</glossterm> to credentials in a remote data system
+     defined by a <glossterm linkend="glossary-foreign-data-wrapper">Foreign Data Wrapper</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createusermapping"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-vacuum">
+   <glossterm>Vacuum</glossterm>
+   <glossdef>
+    <para>
+     The process of removing outdated <acronym>MVCC</acronym>
+     <glossterm linkend="glossary-tuple">Tuple</glossterm>s from a <glossterm linkend="glossary-heap">Heap</glossterm> or
+     <glossterm linkend="glossary-index">Index</glossterm>. This can be initiated through the use of
+     the <command>VACUUM</command> command, but can also be handled automatically
+     via <glossterm linkend="glossary-autovacuum">Autovacuum</glossterm> processes.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-vacuum"/> .
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-view">
+    <glossterm>View</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-relation">Relation</glossterm> that is defined by a
+     <command>SELECT</command> statement, but has no storage of its own.
+     Any time a query references a <glossterm linkend="glossary-view">View</glossterm>, the
+     definition of the <glossterm linkend="glossary-view">View</glossterm> is substituted into the
+     query as if the user had typed that subquery instead of the name of
+     the <glossterm linkend="glossary-view">View</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal-archiver">
+    <glossterm>WAL Archiver (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that saves copies of <glossterm linkend="glossary-wal-file">WAL File</glossterm>s
+     for the purposes of creating backups or keeping
+     <glossterm linkend="glossary-replica">Replica</glossterm>s current.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="continuous-archiving"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal-file">
+    <glossterm>WAL File</glossterm>
+   <glossdef>
+    <para>
+     Each of the numerically-numbered files that provide storage space for
+     <glossterm linkend="glossary-wal">WAL</glossterm>.
+     The files are all of the same predefined size
+     and are written in sequential order, interspersing changes
+     as they occur in multiple simultaneous sessions.
+     If the system crashes, the files are read in order, and each of the
+     changes are replayed to restore the system to the state as it was
+     before the crash.
+    </para>
+    <para>
+     Each WAL file can be released after a
+     <glossterm linkend="glossary-checkpoint">checkpoint</glossterm>
+     writes all the changes in it to the corresponding data files.
+     Releasing the file can be done either by deleting it, or by changing its
+     name so that it will be used in the future, which is called
+     <firstterm>recycling</firstterm>.
+    </para>
+
+    <para>
+     For more information, see
+     <xref linkend="wal-internals"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+    <glossterm>WAL</glossterm>
+   <glosssee otherterm="glossary-wal" />
+  </glossentry>
+
+  <glossentry id="glossary-wal-record">
+    <glossterm>WAL Record</glossterm>
+   <glossdef>
+    <para>
+     A low-level description of an individual data change.
+     It contains sufficient information for the data change to be
+     re-executed (<firstterm>replayed</firstterm>) in case a system failure
+     causes the change to be lost.
+     WAL records use a non-printable binary format.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="wal-internals"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal-segment">
+    <glossterm>WAL Segment</glossterm>
+   <glosssee otherterm="glossary-wal-file" />
+  </glossentry>
+
+  <glossentry id="glossary-wal-writer">
+  <glossterm linkend="glossary-wal-writer">WAL Writer (process)</glossterm>
+  <glossdef>
+   <para>
+    A process that writes <glossterm linkend="glossary-wal-record">WAL records</glossterm>
+    from <glossterm id="linkend-shared-memory">shared memory</glossterm> to
+    <glossterm id="linkend-wal-file">WAL files</glossterm>.
+   </para>
+   <para>
+    For more information, see
+    <xref linkend="runtime-config-wal"/>.
+   </para>
+  </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-window-frame">
+    <glossterm>Window frame</glossterm>
+    <glossdef>
+     <para>
+      In a result set, a subset of neighboring rows that match some user
+      specified criteria form a window frame.
+      For example, in a query that returns employees across several departments,
+      the employees from each specific department can form one window frame.
+     </para>
+    </glossdef>
+   </glossentry>
+
+  <glossentry id="glossary-window-function">
+    <glossterm>Window Function</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm linkend="glossary-function">function</glossterm> whose
+     result is based on values found in
+     <glossterm linkend="glossary-tuple">rows</glossterm> of the same
+     <glossterm linkend="glossary-window-frame">window frame</glossterm>.
+     All <glossterm linkend="glossary-aggregate">aggregate functions</glossterm>
+     can be used as window functions, but window functions can also be
+     used to, for example, give ranks to each of the rows in the window frame.
+     Also known as <firstterm>analytic functions</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="tutorial-window"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal">
+    <glossterm>Write-Ahead Log</glossterm>
+   <glossdef>
+    <para>
+     The journal that keeps track of the changes in the
+     <glossterm linkend="glossary-instance">Instance</glossterm> as user- and system-invoked
+     operations take place.  It comprises many individual
+     <glossterm linkend="glossary-wal-record">WAL records</glossterm> written
+     sequentially to <glossterm linkend="glossary-wal-file">WAL files</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-unique-index">
+    <glossterm>Unique Index</glossterm>
+   <glossdef>
+    <para>
+     TODO - we never defined this and we might just use the component glossterms "unique" and "index"
+    </para>
+   </glossdef>
+  </glossentry>
+ </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 1f7bd32878..ba3d626102 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
   &docguide;
   &limits;
   &acronyms;
+  &glossary;
   &color;
 
  </part>
-- 
2.20.1

diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 1043d0f7ab..cf21ef857e 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
new file mode 100644
index 0000000000..7d981a9223
--- /dev/null
+++ b/doc/src/sgml/glossary.sgml
@@ -0,0 +1,1692 @@
+<appendix id="glossary">
+ <title>Glossary</title>
+ <para>
+  This is a list of terms and their meaning in the context of
+  <productname>PostgreSQL</productname> and relational database
+  systems in general.
+ </para>
+
+ <glosslist>
+  <glossentry id="glossary-aggregate">
+   <glossterm>Aggregate Function</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-function">function</glossterm> that
+     combines (<firstterm>aggregates</firstterm>) multiple input values,
+     for example by counting, averaging or adding,
+     yielding a single output value.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="functions-aggregate"/>.
+    </para>
+    <glossseealso otherterm="glossary-window-function" />
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-analyze">
+   <glossterm>Analyze (operation)</glossterm>
+   <glossdef>
+    <para>
+     The process of collecting statistics from data in
+     <glossterm linkend="glossary-table">tables</glossterm>
+     and other <glossterm linkend="glossary-relation">relations</glossterm>
+     to help the <glossterm linkend="glossary-planner">query planner</glossterm>
+     to make decisions about how to execute
+     <glossterm linkend="glossary-query">queries</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Analytic Function</glossterm>
+   <glosssee otherterm="glossary-window-function" />
+  </glossentry>
+
+  <glossentry id="glossary-atomic">
+   <glossterm>Atomic</glossterm>
+   <glossdef>
+    <para>
+     In reference to a <glossterm linkend="glossary-datum">datum</glossterm>:
+     the fact that its value that cannot be broken down into smaller
+     components.
+    </para>
+   </glossdef>
+   <glossdef>
+    <para>
+     In reference to a
+     <glossterm linkend="glossary-transaction">database transaction</glossterm>:
+     see <glossterm linkend="glossary-atomicity">atomicity</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-atomicity">
+   <glossterm>Atomicity</glossterm>
+   <glossdef>
+    <para>
+     The property of a <glossterm linkend="glossary-transaction">transaction</glossterm>
+     that either all its operations complete as a single unit or none do.
+     In addition, if a system failure occurs during the execution of a
+     transaction, no partial results are visible after recovery.
+     This is one of the <acronym>ACID</acronym> properties.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-attribute">
+   <glossterm>Attribute</glossterm>
+   <glossdef>
+    <para>
+     An element with a certain name and data type found within a
+     <glossterm linkend="glossary-tuple">tuple</glossterm> or
+     <glossterm linkend="glossary-table">table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-autovacuum">
+   <glossterm>Autovacuum (process)</glossterm>
+   <glossdef>
+    <para>
+     A set of background processes that routinely perform
+     <glossterm linkend="glossary-vacuum">vacuum</glossterm>
+     and <glossterm linkend="glossary-analyze">analyze</glossterm>
+     operations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="autovacuum"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-backend">
+   <glossterm>Backend (process)</glossterm>
+   <glossdef>
+    <para>
+     Processes of an <glossterm linkend="glossary-instance">instance</glossterm>
+     which act on behalf of client <glossterm linkend="glossary-session">sessions</glossterm>
+     and handle their requests.
+    </para>
+    <para>
+     (Don't confuse this term with the similar terms
+     <glossterm linkend="glossary-background-worker">Background Worker</glossterm> or
+     <glossterm linkend="glossary-background-writer">Background Writer</glossterm>).
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-background-worker">
+   <glossterm>Background Worker (process)</glossterm>
+   <glossdef>
+    <para>
+     Individual processes within an <glossterm linkend="glossary-instance">instance</glossterm>,
+     which run system- or user-supplied code.
+     They provide infrastructure for several features in
+     <productname>PostgreSQL</productname>, such as 
+     <glossterm linkend="glossary-replication">logical replication</glossterm>
+     and <glossterm linkend="glossary-parallel-query">parallel queries</glossterm>.
+     <glossterm linkend="glossary-extension">Extensions</glossterm> can add
+     custom background worker processes, as well.
+   </para>
+   <para>
+    For more information, see
+    <xref linkend="bgworker"/>.
+   </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-background-writer">
+   <glossterm>Background Writer (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that continuously writes dirty pages from
+     <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm> to
+     the file system.  It wakes up periodically, but works only for a short
+     period in order to distribute its expensive <acronym>I/O</acronym>
+     activity over time, instead of generating fewer larger
+     <acronym>I/O</acronym> peaks which could block other processes.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-resource"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-cast">
+   <glossterm>Cast</glossterm>
+   <glossdef>
+    <para>
+     A conversion of a <glossterm linkend="glossary-datum">Datum</glossterm>
+     from its current data type to another data type.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-catalog">
+   <glossterm>Catalog</glossterm>
+   <glossdef>
+    <para>
+     The <acronym>SQL</acronym> standard uses this term to
+     indicate what is called a
+     <glossterm linkend="glossary-database">Database</glossterm> in
+     <productname>PostgreSQL</productname>'s terminology.
+    </para>
+    <para>
+     This should not be confused with the
+     <glossterm linkend="glossary-system-catalog">System Catalog</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-check-constraint">
+   <glossterm>Check Constraint</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm linkend="glossary-constraint">constraint</glossterm>
+     defined on a <glossterm linkend="glossary-relation">relation</glossterm>
+     which restricts the values allowed in one or more
+     <glossterm linkend="glossary-attribute">attributes</glossterm>. The
+     check constraint can make reference to any attribute of the same row in
+     the relation, but cannot reference other rows of the same relation or
+     other relations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-constraints"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-checkpointer">
+   <glossterm>Checkpointer (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that writes dirty pages to the file system and creates a special
+     checkpoint WAL record. This process is initiated when predefined
+     conditions are met, such as a specified amount of time has passed, or
+     a certain volume of records has been written.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-checkpoint">
+   <glossterm>Checkpoint</glossterm>
+   <glossdef>
+    <para>
+     A point in the <glossterm linkend="glossary-wal">WAL</glossterm> sequence
+     at which it is guaranteed that the heap and index data files have been
+     updated with all information from
+     <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm>
+     modified before that checkpoint;
+     a <firstterm>checkpoint record</firstterm> is written and flushed to WAL
+     to mark that point.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="wal-configuration"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Class (archaic)</glossterm>
+   <glosssee otherterm="glossary-relation" />
+  </glossentry>
+
+  <glossentry id="glossary-client">
+   <glossterm>Client (process)</glossterm>
+   <glossdef>
+    <para>
+     Any process, possibly remote, that establishes a
+     <glossterm linkend="glossary-session">session</glossterm>
+     by <glossterm linkend="glossary-connection">connecting</glossterm> to an
+     <glossterm linkend="glossary-instance">instance</glossterm>
+     to interact with a <glossterm linkend="glossary-database">database</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-cluster">
+   <glossterm>Cluster</glossterm>
+   <glossdef>
+    <para>
+     A group of <glossterm linkend="glossary-database">Databases</glossterm> plus their
+     <glossterm linkend="glossary-global-sql-object">Global SQL Objects</glossterm>. The
+     <firstterm>cluster</firstterm> is managed by exactly one
+     <glossterm linkend="glossary-instance">Instance</glossterm>. A newly created
+     Cluster will have three databases created automatically. They are
+     <literal>template0</literal>, <literal>template1</literal>, and
+     <literal>postgres</literal>. It is expected that an application will
+     create one or more additional database aside from these three.
+    </para>
+    <para>
+     Don't confuse the <productname>PostgreSQL</productname>-specific term
+     <glossterm linkend="glossary-cluster">Cluster</glossterm> with the SQL
+     command <command>CLUSTER</command>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-column">
+   <glossterm>Column</glossterm>
+   <glossdef>
+    <para>
+     An <glossterm linkend="glossary-attribute">Attribute</glossterm> found in
+     a <glossterm linkend="glossary-table">Table</glossterm> or
+     <glossterm linkend="glossary-view">View</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-commit">
+   <glossterm>Commit</glossterm>
+   <glossdef>
+    <para>
+     The act of finalizing a
+     <glossterm linkend="glossary-transaction">transaction</glossterm> within
+     the <glossterm linkend="glossary-database">Database</glossterm>, which
+     makes it visible to other transactions and assures its
+     <glossterm linkend="glossary-durability">durability</glossterm>.
+    </para>
+   <para>
+    For more information, see
+    <xref linkend="sql-commit"/>.
+   </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-concurrency">
+   <glossterm>Concurrency</glossterm>
+   <glossdef>
+    <para>
+     The concept that multiple independent operations happen within the
+     <glossterm linkend="glossary-database">Database</glossterm> at the same time.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-connection">
+   <glossterm>Connection</glossterm>
+   <glossdef>
+    <para>
+     An established line of communication between a client process and a
+     <glossterm linkend="glossary-backend">backend</glossterm> process,
+     usually over a network, supporting a
+     <glossterm linkend="glossary-session">session</glossterm>.  This term is
+     sometimes used as a synonym for session.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-connection"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-consistency">
+   <glossterm>Consistency</glossterm>
+   <glossdef>
+    <para>
+     The property that the data in the
+     <glossterm linkend="glossary-database">database</glossterm>
+     is always in compliance with
+     <glossterm linkend="glossary-constraint">integrity constraints</glossterm>.
+     Transactions may be allowed to violate some of the constraints
+     transiently before it commits, but if such violations are not fixed
+     by the time it commits, such transaction is automatically
+     <glossterm linkend="glossary-rollback">rolled back</glossterm>.
+     This is one of the <acronym>ACID</acronym> properties.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-constraint">
+   <glossterm>Constraint</glossterm>
+   <glossdef>
+    <para>
+     A restriction on the values of data allowed within a
+     <glossterm linkend="glossary-table">Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-constraints"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Data Area</glossterm>
+   <glosssee otherterm="glossary-data-directory" />
+  </glossentry>
+
+  <glossentry id="glossary-data-directory">
+   <glossterm>Data Directory</glossterm>
+   <glossdef>
+    <para>
+     The base directory on the filesystem of a
+     <glossterm linkend="glossary-server">Server</glossterm> that contains all
+     data files and subdirectories associated with a
+     <glossterm linkend="glossary-cluster">Cluster</glossterm> with the
+     exception of <glossterm linkend="glossary-tablespace">tablespaces</glossterm>.
+     The environment variable <literal>PGDATA</literal> is commonly used to
+     refer to the
+     <glossterm linkend="glossary-data-directory">data directory</glossterm>.
+    </para>
+    <para>
+     An <glossterm linkend="glossary-instance">instance</glossterm>'s storage
+     space comprises the data directory plus any additional tablespaces.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="storage-file-layout"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-database">
+   <glossterm>Database</glossterm>
+   <glossdef>
+    <para>
+     A named collection of
+     <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Database Server</glossterm>
+   <glosssee otherterm="glossary-instance" />
+  </glossentry>
+
+  <glossentry id="glossary-datum">
+   <glossterm>Datum</glossterm>
+   <glossdef>
+    <para>
+     The internal representation of one value of a <acronym>SQL</acronym>
+     data type.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-delete">
+   <glossterm>Delete</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command which removes
+     <glossterm linkend="glossary-tuple">Row</glossterm>s from a given
+     <glossterm linkend="glossary-table">Table</glossterm>
+     or <glossterm linkend="glossary-relation">Relation</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-delete"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-durability">
+   <glossterm>Durability</glossterm>
+   <glossdef>
+    <para>
+     The assurance that once a
+     <glossterm linkend="glossary-transaction">transaction</glossterm> has
+     been <glossterm linkend="glossary-commit">Committed</glossterm>, the
+     changes remain even after a system failure or crash.
+     This is one of the <acronym>ACID</acronym> properties. 
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-extension">
+   <glossterm>Extension</glossterm>
+   <glossdef>
+    <para>
+     A software add-on package that can be installed on an
+     <glossterm linkend="glossary-instance">instance</glossterm> to
+     get extra features.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="extend-extensions" />.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-file-segment">
+   <glossterm>File Segment</glossterm>
+   <glossdef>
+    <para>
+     A physical file which stores data for a given
+     <glossterm linkend="glossary-heap">Heap</glossterm> or
+     <glossterm linkend="glossary-index">Index</glossterm> object.
+     <glossterm linkend="glossary-file-segment">File Segment</glossterm>s are
+     limited in size by a configuration value and if that size is exceeded, it
+     will be split into multiple physical files.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="storage-file-layout"/>.
+    </para>
+    <para>
+     (Don't confuse this term with the similar term
+     <glossterm linkend="glossary-wal-file">WAL Segment</glossterm>).
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-data-wrapper">
+   <glossterm>Foreign Data Wrapper</glossterm>
+   <glossdef>
+    <para>
+     A means of representing data that is not contained in the local
+     <glossterm linkend="glossary-database">Database</glossterm> so that it appears as if were in local
+     <glossterm linkend="glossary-table">Table</glossterm>(s). With a Foreign Data Wrapper it is
+     possible to define a <glossterm linkend="glossary-foreign-server">Foreign Server</glossterm> and
+     <glossterm linkend="glossary-foreign-table">Foreign Table</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createforeigndatawrapper"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-key">
+   <glossterm>Foreign Key</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm linkend="glossary-constraint">Constraint</glossterm>
+     defined on one or more <glossterm linkend="glossary-column">Column</glossterm>s
+     in a <glossterm linkend="glossary-table">Table</glossterm> which
+     requires the value(s) in those <glossterm linkend="glossary-column">Column</glossterm>s to
+     identify zero or one <glossterm linkend="glossary-tuple">Row</glossterm>
+     in another (or, infrequently, the same)
+     <glossterm linkend="glossary-table">Table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-server">
+   <glossterm>Foreign Server</glossterm>
+   <glossdef>
+    <para>
+     A named collection of
+     <glossterm linkend="glossary-foreign-table">Foreign Table</glossterm>s which
+     all use the same
+     <glossterm linkend="glossary-foreign-data-wrapper">Foreign Data Wrapper</glossterm>
+     and have other configuration values in common.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createserver"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-foreign-table">
+   <glossterm>Foreign Table</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-relation">Relation</glossterm> which appears to have
+     <glossterm linkend="glossary-tuple">rows</glossterm> and
+     <glossterm linkend="glossary-column">columns</glossterm> similar to a
+     regular <glossterm linkend="glossary-table">Table</glossterm>, but will forward
+     requests for data through its
+     <glossterm linkend="glossary-foreign-data-wrapper">Foreign Data Wrapper</glossterm>,
+     which will return <glossterm linkend="glossary-result-set">Result Sets</glossterm>
+     structured according to the definition of the
+     <glossterm linkend="glossary-foreign-table">Foreign Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createforeigntable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-function">
+   <glossterm>Function</glossterm>
+   <glossdef>
+    <para>
+     Any defined transformation of data. Many functions are already defined
+     within <productname>PostgreSQL</productname> itself, but user-defined
+     ones can also be added.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createfunction"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-global-sql-object">
+   <glossterm>Global SQL Object</glossterm>
+   <glossdef>
+    <para>
+     <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s which do
+     not belong to a specific
+     <glossterm linkend="glossary-database">database</glossterm>.
+    </para>
+    <para>
+     These objects are 
+     <glossterm linkend="glossary-role">roles</glossterm>,
+     <glossterm linkend="glossary-tablespace">tablespaces</glossterm>,
+     replication origins, and subscriptions for logical replication.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-grant">
+   <glossterm>Grant</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command that is used to allow
+     <glossterm linkend="glossary-user">User</glossterm>s or <glossterm linkend="glossary-role">Role</glossterm>s to access
+     specific objects within the <glossterm linkend="glossary-database">Database</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-grant"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-heap">
+   <glossterm>Heap</glossterm>
+   <glossdef>
+    <para>
+     Contains the values of <glossterm linkend="glossary-tuple">Row</glossterm>
+     attributes (i.e. the data). The <glossterm linkend="glossary-heap">Heap</glossterm>
+     is realized within <glossterm linkend="glossary-database">Database</glossterm> files.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Host</glossterm>
+   <glosssee otherterm="glossary-server" />
+  </glossentry>
+
+  <glossentry id="glossary-index">
+   <glossterm>Index</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-relation">Relation</glossterm> that contains
+     data derived from a <glossterm linkend="glossary-table">Table</glossterm>
+     (or <glossterm linkend="glossary-relation">Relation</glossterm> types
+     such as a <glossterm linkend="glossary-materialized-view">Materialized View</glossterm>).
+     Its internal structure supports fast retrieval of and access to the original
+     data.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createindex"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-insert">
+   <glossterm>Insert</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command used to add new data into a
+     <glossterm linkend="glossary-table">Table</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-insert"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-instance">
+   <glossterm>Instance</glossterm>
+   <glossdef>
+    <para>
+     An <glossterm>Instance</glossterm> is a group of processes,
+     its supporting <glossterm linkend="glossary-data-directory">storage space</glossterm>,
+     plus their
+     common <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm>,
+     running on a single <glossterm linkend="glossary-server">Server</glossterm>.
+     The <glossterm linkend="glossary-instance">Instance</glossterm>
+     handles all key features of a <acronym>DBMS</acronym>: read and write
+     access to files and shared memory, assurance of
+     the <acronym>ACID</acronym> paradigm, <acronym>MVCC</acronym>,
+     <glossterm linkend="glossary-connection">Connection</glossterm>s to client programs, backup,
+     recovery, replication, privileges, etc.
+    </para>
+    <para>
+     An <glossterm>Instance</glossterm> manages exactly one
+     <glossterm linkend="glossary-cluster">Cluster</glossterm>.
+    </para>
+    <para>
+     Many <glossterm>Instance</glossterm>s can run on the same server as
+     long as their <acronym>TCP/IP</acronym> ports do not conflict.
+     Different instances on a server may use the
+     same or different versions of <productname>PostgreSQL</productname>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-isolation">
+   <glossterm>Isolation</glossterm>
+   <glossdef>
+    <para>
+     The property that the effects of a transaction are not visible to
+     <glossterm linkend="glossary-concurrency">concurrent transactions</glossterm>
+     before it commits.
+     This is one of the <acronym>ACID</acronym> properties.
+    </para>
+    <para>
+     For more information, see <xref linkend="transaction-iso" />.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-join">
+   <glossterm>Join</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> keyword used in <command>SELECT</command> statements for
+     combining data from multiple <glossterm linkend="glossary-relation">Relation</glossterm>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-key">
+   <glossterm>Key</glossterm>
+   <glossdef>
+    <para>
+     A means of identifying a <glossterm linkend="glossary-tuple">Row</glossterm> within a
+     <glossterm linkend="glossary-table">Table</glossterm> or <glossterm linkend="glossary-relation">Relation</glossterm> by
+     values contained within one or more <glossterm linkend="glossary-attribute">Attribute</glossterm>s
+     in that <glossterm linkend="glossary-table">Table</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-lock">
+   <glossterm>Lock</glossterm>
+   <glossdef>
+    <para>
+     A mechanism that allows a process to limit or prevent simultaneous
+     access to a resource.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-log-file">
+   <glossterm>Log File</glossterm>
+   <glossdef>
+    <para>
+     <glossterm>Log File</glossterm>s contain human-readable text lines about
+     events. Examples include login failures, long-running queries, etc.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="logfile-maintenance"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-logger">
+   <glossterm>Logger (process)</glossterm>
+   <glossdef>
+    <para>
+     If activated, the
+     <glossterm linkend="glossary-logger">Logger</glossterm> process
+     writes information about database events into the current
+     <glossterm linkend="glossary-log-file">Log File</glossterm>. When reaching certain time- or
+     volume-dependent criteria, a new log file is created.
+     Also called <firstterm>syslogger</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-logging"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-log-record">
+   <glossterm>Log Record</glossterm>
+    <glossdef>
+     <para>
+      Archaic term for a <glossterm linkend="glossary-wal-record">WAL Record</glossterm>.
+     </para>
+    </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-logged">
+   <glossterm>Logged</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-table">Table</glossterm> is considered
+     <glossterm linkend="glossary-logged">Logged</glossterm> if changes to it are sent to the
+     <glossterm linkend="glossary-wal">WAL</glossterm>. By default, all regular
+     <glossterm linkend="glossary-table">Table</glossterm>s are <glossterm linkend="glossary-logged">Logged</glossterm>. A
+     table can be specified as <glossterm linkend="glossary-unlogged">Unlogged</glossterm> either at
+     creation time or via the <command>ALTER TABLE</command> command.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Master (server)</glossterm>
+   <glosssee otherterm="glossary-primary-server" />
+  </glossentry>
+
+  <glossentry id="glossary-materialized">
+   <glossterm>Materialized</glossterm>
+   <glossdef>
+    <para>
+     The act of storing information rather than just the method of accessing
+     the information. This term is used in <glossterm linkend="glossary-materialized-view">Materialized
+     View</glossterm>s, meaning that the data derived from the
+     <glossterm linkend="glossary-view">View</glossterm> is actually stored on disk separately from
+     the sources of that data. When using the term
+     <glossterm linkend="glossary-materialized">Materialized</glossterm> to refer to
+     multi-step queries, it means that the data of a given step is stored
+     in memory, but that storage may spill over onto disk.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-materialized-view">
+   <glossterm>Materialized View</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-relation">Relation</glossterm> that is defined in the same way that
+     a <glossterm linkend="glossary-view">View</glossterm> is, but stores data in the same way
+     that a <glossterm linkend="glossary-table">Table</glossterm> does. It cannot be modified via
+     <command>INSERT</command>, <command>UPDATE</command>, or
+     <command>DELETE</command> operations.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-creatematerializedview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-mvcc">
+   <glossterm>Multi-version concurrency control (MVCC)</glossterm>
+   <glossdef>
+    <para>
+     A mechanism designed to allow several
+     <glossterm linkend="glossary-transaction">transactions</glossterm> to be
+     reading and writing the same rows without one process causing other
+     processes to stall.
+     In <productname>PostgreSQL</productname>, MVCC is implemented by
+     creating copies (<firstterm>versions</firstterm>) of
+     <glossterm linkend="glossary-tuple">tuples</glossterm> as they are
+     modified; after transactions that can see the old versions terminate,
+     those old versions need to be removed.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-null">
+   <glossterm>Null</glossterm>
+   <glossdef>
+    <para>
+     A concept of non-existence that is a central tenet of Relational
+     Database Theory. It represents the absence of value.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Optimizer</glossterm>
+   <glosssee otherterm="glossary-planner" />
+  </glossentry>
+
+  <glossentry id="glossary-parallel-query">
+   <glossterm>Parallel Query</glossterm>
+   <glossdef>
+    <para>
+     The ability to handle parts of executing a
+     <glossterm linkend="glossary-query">query</glossterm> to take advantage
+     of parallel processes on servers with multiple <acronym>CPU</acronym>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-partition">
+   <glossterm>Partition</glossterm>
+   <glossdef>
+    <para>
+     In reference to a <glossterm linkend="glossary-table">Table</glossterm>:
+     A <glossterm linkend="glossary-table">Table</glossterm> that can be queried directly,
+     or via a partitioned table, which is a collection of
+     sub-tables, each capable of holding one defined
+     subset of information that does not overlap with any other
+     table in the collection.
+    </para>
+   </glossdef>
+   <glossdef>
+    <para>
+     In reference to a <glossterm linkend="glossary-window-function">window function</glossterm>:
+     a partition is a definition that identifies which neighboring
+     <glossterm linkend="glossary-tuple">Row</glossterm>s can be considered by the
+     function.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-postmaster">
+   <glossterm>Postmaster (process)</glossterm>
+   <glossdef>
+    <para>
+      The very first process of an <glossterm linkend="glossary-instance">Instance</glossterm>. It
+      starts and manages the other auxiliary processes and creates
+      <glossterm linkend="glossary-backend">backend processes</glossterm>
+      on demand.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="server-start"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-primary-server">
+   <glossterm>Primary (server)</glossterm>
+   <glossdef>
+    <para>
+     When two or more <glossterm linkend="glossary-database">Database</glossterm>s are linked via
+     <glossterm linkend="glossary-replication">Replication</glossterm>, the <glossterm linkend="glossary-server">Server</glossterm>
+     that is considered the authoritative source of information is called
+     the <firstterm>Primary</firstterm>,
+     also known as a <firstterm>master</firstterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-primary-key">
+   <glossterm>Primary Key</glossterm>
+   <glossdef>
+    <para>
+     A special case of a
+     <glossterm linkend="glossary-unique-constraint">unique constraint</glossterm>
+     defined on a
+     <glossterm linkend="glossary-table">Table</glossterm> or other
+     <glossterm linkend="glossary-relation">Relation</glossterm> that also
+     guarantees that all of the
+     <glossterm linkend="glossary-attribute">Attribute</glossterm>s
+     within the <glossterm linkend="glossary-primary-key">Primary Key</glossterm>
+     do not have <glossterm linkend="glossary-null">Null</glossterm> values.
+     As the name implies, there can be only one
+     primary key per table, though it is possible to have multiple unique
+     constraints that also have no null-capable attributes.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-procedure">
+   <glossterm>Procedure</glossterm>
+   <glossdef>
+    <para>
+     A defined set of instructions for manipulating data within a
+     <glossterm linkend="glossary-database">Database</glossterm>.
+     A <glossterm linkend="glossary-procedure">Procedure</glossterm> can
+     be written in a variety of programming languages. They may seem
+     similar to <glossterm linkend="glossary-function">Functions</glossterm>,
+     but are different in that they must be invoked via the <command>CALL</command>
+     command rather than the <command>SELECT</command> or <command>PERFORM</command>
+     commands, and they are allowed to make transactional statements such
+     as <command>COMMIT</command> and <command>ROLLBACK</command>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createprocedure"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-query">
+   <glossterm>Query</glossterm>
+   <glossdef>
+    <para>
+     A request sent by a client to a <glossterm linkend="glossary-backend">backend</glossterm>,
+     usually to return results or to modify data on the database.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-planner">
+   <glossterm>Query Planner</glossterm>
+   <glossdef>
+    <para>
+     The part of <productname>PostgreSQL</productname> that is devoted to
+     determining (<firstterm>planning</firstterm>) the most efficient way to
+     execute <glossterm linkend="glossary-query">queries</glossterm>.
+     Also known as <firstterm>query optimizer</firstterm>,
+     <firstterm>optimizer</firstterm>, or simply <firstterm>planner</firstterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Record</glossterm>
+   <glosssee otherterm="glossary-tuple" />
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Recycling</glossterm>
+   <glosssee otherterm="glossary-wal-file" />
+  </glossentry>
+
+  <glossentry id="glossary-referential-integrity">
+   <glossterm>Referential Integrity</glossterm>
+   <glossdef>
+    <para>
+     A means of restricting data in one <glossterm linkend="glossary-relation">Relation</glossterm>
+     by a <glossterm linkend="glossary-foreign-key">Foreign Key</glossterm>
+     so that it must have matching data in another
+     <glossterm linkend="glossary-relation">Relation</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-relation">
+   <glossterm>Relation</glossterm>
+   <glossdef>
+    <para>
+     The generic term for all objects in a <glossterm linkend="glossary-database">Database</glossterm>
+     that have a name and a list of <glossterm linkend="glossary-attribute">Attribute</glossterm>s
+     defined in a specific order. <glossterm linkend="glossary-table">Table</glossterm>s,
+     <glossterm linkend="glossary-view">View</glossterm>s, <glossterm linkend="glossary-foreign-table">Foreign Table</glossterm>s,
+     <glossterm linkend="glossary-materialized-view">Materialized View</glossterm>s, and
+     <glossterm linkend="glossary-index">Index</glossterm>es are all relations.
+    </para>
+    <para>
+     <firstterm>Class</firstterm> is an archaic synonym for
+     <firstterm>relation</firstterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-replica">
+   <glossterm>Replica</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-database">Database</glossterm> that is paired with a
+     <glossterm linkend="glossary-primary-server">primary</glossterm>
+     database and is maintaining a copy of some or
+     all of the primary <glossterm linkend="glossary-database">Database</glossterm>'s data. The foremost
+     reasons for doing this are to allow for greater access to that data,
+     and to maintain availability of the data in the event that the
+     <glossterm linkend="glossary-primary-server">primary</glossterm> becomes unavailable.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-replication">
+   <glossterm>Replication</glossterm>
+   <glossdef>
+    <para>
+     The act of reproducing data on one <glossterm linkend="glossary-server">Server</glossterm> onto
+     another server called a <glossterm linkend="glossary-replica">Replica</glossterm>. This can take the
+     form of <firstterm>physical replication</firstterm>, where all file
+     changes from one server are copied verbatim,
+     or <firstterm>logical replication</firstterm> where a defined subset
+     of data changes are conveyed using a higher-level representation.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-result-set">
+   <glossterm>Result Set</glossterm>
+   <glossdef>
+    <para>
+     A data structure transmitted from a <glossterm linkend="glossary-backend">Backend Process</glossterm> to
+     client program upon the completion of a <acronym>SQL</acronym>
+     command, usually a <command>SELECT</command> but it can be an
+     <command>INSERT</command>, <command>UPDATE</command>, or
+     <command>DELETE</command> command if the <literal>RETURNING</literal>
+     clause is specified. The data structure consists of zero or more
+     <glossterm linkend="glossary-tuple">Row</glossterm>s with the same ordered set of
+     <glossterm linkend="glossary-attribute">Attribute</glossterm>s.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-revoke">
+   <glossterm>Revoke</glossterm>
+   <glossdef>
+    <para>
+     A command to prevent access to a named set of
+     <glossterm linkend="glossary-database">Database</glossterm> objects for a named list of
+     <glossterm linkend="glossary-user">User</glossterm>s and <glossterm linkend="glossary-role">Role</glossterm>s.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-revoke"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-role">
+   <glossterm>Role</glossterm>
+   <glossdef>
+    <para>
+     A collection of access privileges to the
+     <glossterm linkend="glossary-database">Database</glossterm>. <glossterm linkend="glossary-role">Role</glossterm>s are
+     themselves a privilege that can be granted to other roles. This is
+     often done for convenience or to ensure completeness when multiple
+     <glossterm linkend="glossary-user">User</glossterm>s need the same privileges.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createrole"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-rollback">
+   <glossterm>Rollback</glossterm>
+   <glossdef>
+    <para>
+     A command to undo all of the operations performed since the beginning
+     of a <glossterm linkend="glossary-transaction">Transaction</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-rollback"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Row</glossterm>
+   <glosssee otherterm="glossary-tuple" />
+  </glossentry>
+
+  <glossentry id="glossary-savepoint">
+   <glossterm>Savepoint</glossterm>
+   <glossdef>
+    <para>
+     A special mark inside the sequence of steps in a
+     <glossterm linkend="glossary-transaction">Transaction</glossterm>. Data modifications after this
+     point in time may be reverted to the time of the savepoint.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-savepoint"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-schema">
+   <glossterm>Schema</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-schema">Schema</glossterm> is a namespace for
+     <glossterm linkend="glossary-sql-object">SQL object</glossterm>s, which all reside in the same
+     <glossterm linkend="glossary-database">database</glossterm>.  Each
+     <glossterm linkend="glossary-sql-object">SQL object</glossterm> must reside in exactly one
+     <glossterm linkend="glossary-schema">Schema</glossterm>.
+    </para>
+    <para>
+     The names of <glossterm linkend="glossary-sql-object">SQL Objects</glossterm>
+     of the same type in the same schema are enforced unique.  There is no
+     restriction on reusing a name in multiple schemas.
+    </para>
+    <para>
+     Many <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s reside in the default
+     <glossterm linkend="glossary-schema">Schema</glossterm> <literal>public</literal>, but it is
+     expected that more schemas are created to hold application-specific
+     <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s.
+    </para>
+   </glossdef>
+   <glossdef>
+    <para>
+     More generically, the term <firstterm>Schema</firstterm> is used to mean all data descriptions
+     (<glossterm linkend="glossary-table">Table</glossterm> definitions,
+     <glossterm linkend="glossary-constraint">Constraint</glossterm>s, comments, etc)
+     for a given <glossterm linkend="glossary-database">Database</glossterm> or
+     subset thereof.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="ddl-schemas"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>Segment</glossterm>
+   <glosssee otherterm="glossary-file-segment" />
+  </glossentry>
+
+  <glossentry id="glossary-select">
+   <glossterm>Select</glossterm>
+   <glossdef>
+    <para>
+     The <acronym>SQL</acronym> command used to query a <glossterm linkend="glossary-database">Database</glossterm>.
+     Normally, <command>SELECT</command>s are not expected to modify the
+     <glossterm linkend="glossary-database">Database</glossterm> in any way, but it is possible that
+     <glossterm linkend="glossary-function">Function</glossterm>s invoked within the query could have
+     side effects that do modify data.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-select"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-serializable">
+   <glossterm>Serializable</glossterm>
+   <glossdef>
+    <para>
+     Transactions defined as <literal>SERIALIZABLE</literal> are unable to
+     see changes made within other transactions. In effect, for the
+     initializing session the entire <glossterm linkend="glossary-database">Database</glossterm>
+     appears to be frozen for the duration of the
+     <glossterm linkend="glossary-transaction">Transaction</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-server">
+   <glossterm>Server</glossterm>
+   <glossdef>
+    <para>
+     A computer on which <productname>PostgreSQL</productname>
+     <glossterm linkend="glossary-instance">instances</glossterm> run.
+     The term <firstterm>server</firstterm> denotes real hardware, a
+     container, or a Virtual Machine.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-session">
+   <glossterm>Session</glossterm>
+   <glossdef>
+    <para>
+     A state that allows a client and a backend to interact,
+     communicating over a <glossterm linkend="glossary-connection">connection</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-sequence">
+   <glossterm>Sequence</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-database">Database</glossterm> object which
+     represents the mathematical concept of a numerical integral sequence.
+     It can be thought of as a <glossterm linkend="glossary-table">Table</glossterm>
+     with exactly one <glossterm linkend="glossary-tuple">Row</glossterm> and
+     one <glossterm linkend="glossary-column">Column</glossterm>. The
+     value stored is known as the current value. A
+     <glossterm linkend="glossary-sequence">Sequence</glossterm> has a defined
+     direction (usually increasing) and an interval step (usually 1).
+     Whenever the <literal>NEXTVAL</literal> pseudo-column of a
+     <glossterm linkend="glossary-sequence">Sequence</glossterm> is accessed,
+     the current value is moved in the defined direction by the defined
+     interval step, that value is returned to the invoking query,
+     and the current value of the sequence is updated to reflect the new value.
+     The value can be updated multiple times in a single query,
+     the net effect being that each row selected will have a different value.
+     Values taken from a
+     <glossterm linkend="glossary-sequence">Sequence</glossterm> are never
+     reverted, even in the case of a
+     <glossterm linkend="glossary-rollback">Rollback</glossterm>, which means
+     that the <glossterm linkend="glossary-sequence">Sequence</glossterm>
+     will never generate the same number twice, which makes it useful for
+     generating
+     <glossterm linkend="glossary-primary-key">Primary Key</glossterm> values.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createsequence"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-shared-memory">
+   <glossterm>Shared Memory</glossterm>
+   <glossdef>
+    <para>
+     <acronym>RAM</acronym> which is used by the processes common to an
+     <glossterm linkend="glossary-instance">Instance</glossterm>. It mirrors parts of
+     <glossterm linkend="glossary-database">Database</glossterm> files, provides an area for
+     <glossterm linkend="glossary-wal-record">WAL Record</glossterm>s, and stores additional common
+     information. Note that <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm> belongs to
+     the complete <glossterm linkend="glossary-instance">Instance</glossterm>, not to a single
+     <glossterm linkend="glossary-database">Database</glossterm>.
+    </para>
+    <para>
+     <glossterm linkend="glossary-shared-memory">Shared Memory</glossterm> is organized into pages. If a
+     page is modified, it is called a dirty page until it is written back
+     to the file system.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-resource-memory"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-sql-object">
+   <glossterm>SQL Object</glossterm>
+    <glossdef>
+     <para>
+      A <glossterm linkend="glossary-table">table</glossterm>,
+      <glossterm linkend="glossary-view">view</glossterm>,
+      <glossterm linkend="glossary-materialized-view">materialized view</glossterm>,
+      <glossterm linkend="glossary-index">index</glossterm>,
+      <glossterm linkend="glossary-constraint">constraint</glossterm>,
+      <glossterm linkend="glossary-sequence">sequence</glossterm>,
+      <glossterm linkend="glossary-function">function</glossterm>,
+      <glossterm linkend="glossary-procedure">procedure</glossterm>,
+      <glossterm linkend="glossary-trigger">trigger</glossterm>,
+      data type, or operator. Every one of those SQL objects
+      belong to exactly one <glossterm linkend="glossary-schema">Schema</glossterm>.
+    </para>
+    <para>
+     There also exist SQL objects that do not belong to schemas; those include
+     <glossterm linkend="glossary-extension">extensions</glossterm>,
+     <glossterm linkend="glossary-cast">data type cases</glossterm>,
+     and
+     <glossterm linkend="glossary-foreign-data-wrapper">foreign data wrappers</glossterm>.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="manage-ag-overview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-stats-collector">
+   <glossterm>Stats Collector</glossterm>
+   <glossdef>
+    <para>
+     This process collects statistical information about the
+     <glossterm linkend="glossary-cluster">Cluster</glossterm>'s activities.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="monitoring-stats"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-system-catalog">
+   <glossterm>System Catalog</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm linkend="glossary-table">Table</glossterm>s and
+     <glossterm linkend="glossary-view">View</glossterm>s which describe the structure of all
+     <acronym>SQL</acronym> objects of the <glossterm linkend="glossary-database">Database</glossterm>
+     and the <glossterm linkend="glossary-global-sql-object">Global SQL Object</glossterm>s of the
+     <glossterm linkend="glossary-cluster">Cluster</glossterm>. The <glossterm linkend="glossary-system-catalog">System
+     Catalog</glossterm> resides in the schema
+     <literal>pg_catalog</literal>. Main parts are mirrored as
+     <glossterm linkend="glossary-view">View</glossterm>s in the <glossterm linkend="glossary-schema">Schema</glossterm>
+     <literal>information_schema</literal>.
+    </para>
+    <para>
+      For more information, see
+      <xref linkend="ddl-schemas"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-table">
+   <glossterm>Table</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm linkend="glossary-tuple">tuples</glossterm> having
+     a common data structure (the same number of
+     <glossterm linkend="glossary-attribute">attributes</glossterm>, in the same
+     order, having the same name and type per position).
+     A table is the most common form of
+     <glossterm linkend="glossary-relation">Relation</glossterm> in
+     <productname>PostgreSQL</productname>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-tablespace">
+   <glossterm>Tablespace</glossterm>
+   <glossdef>
+    <para>
+     A named location on the server filesystem. All <glossterm linkend="glossary-sql-object">SQL Object</glossterm>s
+     which require storage beyond their definition in the
+     <glossterm linkend="glossary-system-catalog">System Catalog</glossterm>
+     must belong to a single tablespace.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="manage-ag-tablespaces"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-temporary-table">
+   <glossterm>Temporary Table</glossterm>
+   <glossdef>
+    <para>
+     <glossterm linkend="glossary-table">Table</glossterm>s that exist either
+     for the lifetime of a
+     <glossterm linkend="glossary-session">Session</glossterm> or a
+     <glossterm linkend="glossary-transaction">Transaction</glossterm>, as
+     specified at the time of creation. The data in them is not visible to
+     other sessions, and is not
+     <glossterm linkend="glossary-logged">Logged</glossterm>.
+     Temporary tables are often used to store intermediate data for a
+     multi-step operation.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtable"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-transaction">
+   <glossterm>Transaction</glossterm>
+   <glossdef>
+    <para>
+     A combination of commands that must act as a single
+     <glossterm linkend="glossary-atomic">Atomic</glossterm> command: they all
+     succeed or all fail as a single unit, and their effects are not visible to
+     other <glossterm linkend="glossary-session">Session</glossterm>s until
+     the transaction is complete.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="transaction-iso"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-trigger">
+   <glossterm>Trigger</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-function">Function</glossterm> which can be defined to execute
+     whenever a certain operation (<command>INSERT</command>,
+     <command>UPDATE</command>, <command>DELETE</command>,
+     <command>TRUNCATE</command>) is applied to a <glossterm linkend="glossary-relation">Relation</glossterm>.
+     A <glossterm linkend="glossary-trigger">Trigger</glossterm>
+     executes within the same <glossterm linkend="glossary-transaction">Transaction</glossterm> as the
+     statement which invoked it, and if the <glossterm linkend="glossary-function">Function</glossterm>
+     fails, then the invoking statement also fails.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createtrigger"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-tuple">
+   <glossterm>Tuple</glossterm>
+   <glossdef>
+    <para>
+     A collection of <glossterm linkend="glossary-attribute">Attribute</glossterm>s in a fixed order.
+     That order may be defined by the <glossterm linkend="glossary-table">Table</glossterm> where
+     the <glossterm linkend="glossary-tuple">Tuple</glossterm> is found, in which case the
+     <glossterm linkend="glossary-tuple">Tuple</glossterm> is often called a
+     row or record.
+     It may also be defined by the structure of a
+     <glossterm linkend="glossary-result-set">Result Set</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-unique-constraint">
+   <glossterm>Unique Constraint</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm linkend="glossary-constraint">constraint</glossterm>
+     defined on a <glossterm linkend="glossary-relation">relation</glossterm>
+     which restricts the values allowed in one or a combination of columns
+     so that each value or combination of values can only appear once in the
+     relation &mdash; that is, no other row in the relation contains values
+     that are equal to those.
+    </para>
+    <para>
+     Because <glossterm linkend="glossary-null">null values</glossterm> are
+     not considered equal to each other, multiple rows with null values are
+     allowed to exist without violating the unique constraint.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-unlogged">
+   <glossterm>Unlogged</glossterm>
+   <glossdef>
+    <para>
+     Changes to an unlogged <glossterm linkend="glossary-relation">Relation</glossterm>
+     are not reflected in the <glossterm linkend="glossary-wal">WAL</glossterm>.
+     This disables replication and crash recovery for these relations.
+    </para>
+    <para>
+     The primary use of unlogged tables is for storing
+     transient work data that must be shared across processes.
+    </para>
+    <para>
+     <glossterm linkend="glossary-temporary-table">Temporary Table</glossterm>s are always unlogged.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-update">
+   <glossterm>Update</glossterm>
+   <glossdef>
+    <para>
+     A <acronym>SQL</acronym> command used to modify
+     <glossterm linkend="glossary-tuple">rows</glossterm>
+     that may already exist in a specified <glossterm linkend="glossary-table">Table</glossterm>.
+     It cannot create or remove rows.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-update"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-user">
+   <glossterm>User</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-role">Role</glossterm> that has the <literal>LOGIN</literal>
+     privilege is said to be a <glossterm linkend="glossary-user">User</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-user-mapping">
+   <glossterm>User Mapping</glossterm>
+   <glossdef>
+    <para>
+     The translation of login credentials in the local
+     <glossterm linkend="glossary-database">Database</glossterm> to credentials
+     in a remote data system defined by a
+     <glossterm linkend="glossary-foreign-data-wrapper">Foreign Data Wrapper</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createusermapping"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-vacuum">
+   <glossterm>Vacuum</glossterm>
+   <glossdef>
+    <para>
+     The process of removing outdated <glossterm linkend="glossary-tuple">tuple
+     versions</glossterm> from tables, and other closely related
+     garbage-collection-like processing required by <productname>PostgreSQL</productname>'s
+     implementation of <glossterm linkend="glossary-mvcc">MVCC</glossterm>.
+     This can be initiated through the use of
+     the <command>VACUUM</command> command, but can also be handled automatically
+     via <glossterm linkend="glossary-autovacuum">Autovacuum</glossterm> processes.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="routine-vacuuming"/> .
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-view">
+   <glossterm>View</glossterm>
+   <glossdef>
+    <para>
+     A <glossterm linkend="glossary-relation">Relation</glossterm> that is defined by a
+     <command>SELECT</command> statement, but has no storage of its own.
+     Any time a query references a <glossterm linkend="glossary-view">View</glossterm>, the
+     definition of the <glossterm linkend="glossary-view">View</glossterm> is substituted into the
+     query as if the user had typed that subquery instead of the name of
+     the <glossterm linkend="glossary-view">View</glossterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="sql-createview"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal-archiver">
+   <glossterm>WAL Archiver (process)</glossterm>
+   <glossdef>
+    <para>
+     A process that saves copies of <glossterm linkend="glossary-wal-file">WAL File</glossterm>s
+     for the purposes of creating backups or keeping
+     <glossterm linkend="glossary-replica">Replica</glossterm>s current.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="continuous-archiving"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal-file">
+   <glossterm>WAL File</glossterm>
+   <glossdef>
+    <para>
+     Also known as <firstterm>WAL segment</firstterm> or
+     <firstterm>WAL segment file</firstterm>.
+     Each of the numerically-numbered files that provide storage space for
+     <glossterm linkend="glossary-wal">WAL</glossterm>.
+     The files are all of the same predefined size
+     and are written in sequential order, interspersing changes
+     as they occur in multiple simultaneous sessions.
+     If the system crashes, the files are read in order, and each of the
+     changes are replayed to restore the system to the state as it was
+     before the crash.
+    </para>
+    <para>
+     Each WAL file can be released after a
+     <glossterm linkend="glossary-checkpoint">checkpoint</glossterm>
+     writes all the changes in it to the corresponding data files.
+     Releasing the file can be done either by deleting it, or by changing its
+     name so that it will be used in the future, which is called
+     <firstterm>recycling</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="wal-internals"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>WAL</glossterm>
+   <glosssee otherterm="glossary-wal" />
+  </glossentry>
+
+  <glossentry id="glossary-wal-record">
+   <glossterm>WAL Record</glossterm>
+   <glossdef>
+    <para>
+     A low-level description of an individual data change.
+     It contains sufficient information for the data change to be
+     re-executed (<firstterm>replayed</firstterm>) in case a system failure
+     causes the change to be lost.
+     WAL records use a non-printable binary format.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="wal-internals"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry>
+   <glossterm>WAL Segment</glossterm>
+   <glosssee otherterm="glossary-wal-file" />
+  </glossentry>
+
+  <glossentry id="glossary-wal-writer">
+  <glossterm>WAL Writer (process)</glossterm>
+  <glossdef>
+   <para>
+    A process that writes <glossterm linkend="glossary-wal-record">WAL records</glossterm>
+    from <glossterm id="linkend-shared-memory">shared memory</glossterm> to
+    <glossterm id="linkend-wal-file">WAL files</glossterm>.
+   </para>
+   <para>
+    For more information, see
+    <xref linkend="runtime-config-wal"/>.
+   </para>
+  </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-window-function">
+   <glossterm>Window Function</glossterm>
+   <glossdef>
+    <para>
+     A type of <glossterm linkend="glossary-function">function</glossterm> whose
+     result is based on values found in
+     <glossterm linkend="glossary-tuple">rows</glossterm> of the same
+     <glossterm linkend="glossary-partition">partition</glossterm>.
+     All <glossterm linkend="glossary-aggregate">aggregate functions</glossterm>
+     can be used as window functions, but window functions can also be
+     used to, for example, give ranks to each of the rows in the partition.
+     Also known as <firstterm>analytic functions</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="tutorial-window"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
+  <glossentry id="glossary-wal">
+   <glossterm>Write-Ahead Log</glossterm>
+   <glossdef>
+    <para>
+     The journal that keeps track of the changes in the
+     <glossterm linkend="glossary-instance">Instance</glossterm> as user- and system-invoked
+     operations take place.  It comprises many individual
+     <glossterm linkend="glossary-wal-record">WAL records</glossterm> written
+     sequentially to <glossterm linkend="glossary-wal-file">WAL files</glossterm>.
+    </para>
+   </glossdef>
+  </glossentry>
+ </glosslist>
+</appendix>
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 1f7bd32878..ba3d626102 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@
   &docguide;
   &limits;
   &acronyms;
+  &glossary;
   &color;
 
  </part>

diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index 8c6cb6e942..b5155e1a85 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -48,7 +48,7 @@
    <glossdef>
     <para>
      In reference to a <glossterm linkend="glossary-datum">datum</glossterm>:
-     the fact that its value that cannot be broken down into smaller
+     the fact that its value cannot be broken down into smaller
      components.
     </para>
    </glossdef>
@@ -270,14 +270,14 @@
      <glossterm linkend="glossary-global-sql-object">global SQL objects</glossterm>. The
      <firstterm>cluster</firstterm> is managed by exactly one
      <glossterm linkend="glossary-instance">instance</glossterm>. A newly created
-     Cluster will have three databases created automatically. They are
+     cluster will have three databases created automatically. They are
      <literal>template0</literal>, <literal>template1</literal>, and
      <literal>postgres</literal>. It is expected that an application will
      create one or more additional database aside from these three.
     </para>
     <para>
      (Don't confuse the <productname>PostgreSQL</productname>-specific term
-     <glossterm linkend="glossary-cluster">Cluster</glossterm> with the SQL
+     <glossterm linkend="glossary-cluster">cluster</glossterm> with the SQL
      command <command>CLUSTER</command>).
     </para>
    </glossdef>
@@ -363,7 +363,7 @@
    <glossdef>
     <para>
      A restriction on the values of data allowed within a
-     <glossterm linkend="glossary-table">Table</glossterm>.
+     <glossterm linkend="glossary-table">table</glossterm>.
     </para>
     <para>
      For more information, see
@@ -424,7 +424,7 @@
    <glossterm>Datum</glossterm>
    <glossdef>
     <para>
-     The internal representation of one value of a <acronym>SQL</acronym>
+     The internal representation of one value of an <acronym>SQL</acronym>
      data type.
     </para>
    </glossdef>
@@ -617,7 +617,7 @@
    <glossdef>
     <para>
      Contains the values of <glossterm linkend="glossary-tuple">row</glossterm>
-     attributes (i.e. the data) for a
+     attributes (i.e., the data) for a
      <glossterm linkend="glossary-relation">relation</glossterm>.
      The heap is realized within
      <glossterm linkend="glossary-file-segment">segment files</glossterm>.
@@ -835,7 +835,7 @@
    <glossdef>
     <para>
      A <glossterm linkend="glossary-relation">relation</glossterm> that is
-     defined in the same way that a a <glossterm linkend="glossary-view">view</glossterm>
+     defined in the same way that a <glossterm linkend="glossary-view">view</glossterm>
      is, but stores data in the same way that a
      <glossterm linkend="glossary-table">table</glossterm> does. It cannot be
      modified via <command>INSERT</command>, <command>UPDATE</command>, or
@@ -900,7 +900,7 @@
     <para>
      In reference to a
      <glossterm linkend="glossary-partitioned-table">partitioned table</glossterm>:
-     One of the tables that each contain part of the data of the partitioned table,
+     One of multiple tables that each contain part of the data of the partitioned table,
      which is said to be the <firstterm>parent</firstterm>.
      The partition is itself a table, so it can also be queried directly;
      at the same time, a partition can sometimes be a partitioned table,
@@ -910,7 +910,7 @@
    <glossdef>
     <para>
      In reference to a <glossterm linkend="glossary-window-function">window function</glossterm>:
-     a partition is a user-defined criteria that identifies which neighboring
+     a partition is a user-defined criterion that identifies which neighboring
      <glossterm linkend="glossary-tuple">rows</glossterm> can be considered by the
      function.
     </para>
@@ -1103,7 +1103,7 @@
     <para>
      A data structure transmitted from a
      <glossterm linkend="glossary-backend">backend process</glossterm> to
-     client program upon the completion of a <acronym>SQL</acronym>
+     client program upon the completion of an <acronym>SQL</acronym>
      command, usually a <command>SELECT</command> but it can be an
      <command>INSERT</command>, <command>UPDATE</command>, or
      <command>DELETE</command> command if the <literal>RETURNING</literal>
@@ -1134,8 +1134,8 @@
    <glossdef>
     <para>
      A collection of access privileges to the
-     <glossterm linkend="glossary-database">instance</glossterm>.
-     Roless are themselves a privilege that can be granted to other roles.
+     <glossterm linkend="glossary-instance">instance</glossterm>.
+     Roles are themselves a privilege that can be granted to other roles.
      This is often done for convenience or to ensure completeness
      when multiple <glossterm linkend="glossary-user">users</glossterm> need
      the same privileges.
@@ -1151,7 +1151,7 @@
    <glossterm>Rollback</glossterm>
    <glossdef>
     <para>
-     A command to undo all of the operations performed since the beginning
+     A command to undo all operations performed since the beginning
      of a <glossterm linkend="glossary-transaction">transaction</glossterm>.
     </para>
     <para>
@@ -1170,7 +1170,7 @@
    <glossterm>Savepoint</glossterm>
    <glossdef>
     <para>
-     A special mark inside the sequence of steps in a
+     A special mark in the sequence of steps in a
      <glossterm linkend="glossary-transaction">transaction</glossterm>.
      Data modifications after this point in time may be reverted
      to the time of the savepoint.
@@ -1192,7 +1192,8 @@
      SQL object must reside in exactly one schema.
     </para>
     <para>
-     The names of SQL objects of the same type in the same schema are enforced unique.
+     The names of SQL objects of the same type in the same schema are enforced
+     to be unique.
      There is no restriction on reusing a name in multiple schemas.
     </para>
     <para>
@@ -1205,7 +1206,7 @@
    </glossdef>
    <glossdef>
     <para>
-     More generically, the term <firstterm>Schema</firstterm> is used to mean
+     More generically, the term <firstterm>schema</firstterm> is used to mean
      all data descriptions (<glossterm linkend="glossary-table">table</glossterm> definitions,
      <glossterm linkend="glossary-constraint">constraints</glossterm>, comments, etc)
      for a given <glossterm linkend="glossary-database">database</glossterm> or
@@ -1356,7 +1357,7 @@
       <glossterm linkend="glossary-procedure">procedure</glossterm>,
       <glossterm linkend="glossary-trigger">trigger</glossterm>,
       data type, or operator. Every one of those SQL objects
-      belong to exactly one <glossterm linkend="glossary-schema">Schema</glossterm>.
+      belong to exactly one <glossterm linkend="glossary-schema">schema</glossterm>.
     </para>
     <para>
      There also exist SQL objects that do not belong to schemas; those include
@@ -1386,7 +1387,7 @@
    <glossdef>
     <para>
      This process collects statistical information about the
-     <glossterm linkend="glossary-cluster">Cluster</glossterm>'s activities.
+     <glossterm linkend="glossary-cluster">cluster</glossterm>'s activities.
     </para>
     <para>
       For more information, see
@@ -1431,7 +1432,7 @@
      <glossterm linkend="glossary-attribute">attributes</glossterm>, in the same
      order, having the same name and type per position).
      A table is the most common form of
-     <glossterm linkend="glossary-relation">Relation</glossterm> in
+     <glossterm linkend="glossary-relation">relation</glossterm> in
      <productname>PostgreSQL</productname>.
     </para>
     <para>
@@ -1508,7 +1509,7 @@
      <command>UPDATE</command>, <command>DELETE</command>,
      <command>TRUNCATE</command>) is applied to a
      <glossterm linkend="glossary-relation">relation</glossterm>.
-     A Trigger executes within the same
+     A trigger executes within the same
      <glossterm linkend="glossary-transaction">transaction</glossterm> as the
      statement which invoked it, and if the function fails, then the invoking
      statement also fails.
@@ -1620,8 +1621,8 @@
    <glossdef>
     <para>
      The process of removing outdated <glossterm linkend="glossary-tuple">tuple
-     versions</glossterm> from tables, and other closely related
-     garbage-collection-like processing required by <productname>PostgreSQL</productname>'s
+     versions</glossterm> from tables, and other
+     processing required by <productname>PostgreSQL</productname>'s
      implementation of <glossterm linkend="glossary-mvcc">MVCC</glossterm>.
      This can be initiated through the use of
      the <command>VACUUM</command> command, but can also be handled automatically
@@ -1678,7 +1679,7 @@
      and are written in sequential order, interspersing changes
      as they occur in multiple simultaneous sessions.
      If the system crashes, the files are read in order, and each of the
-     changes are replayed to restore the system to the state as it was
+     changes is replayed to restore the system to the state as it was
      before the crash.
     </para>
     <para>

diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index 8c6cb6e942..25762b7c3a 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -208,15 +208,6 @@
    </glossdef>
   </glossentry>
 
-  <glossentry id="glossary-checkpointer">
-   <glossterm>Checkpointer (process)</glossterm>
-   <glossdef>
-    <para>
-     A specialized process responsible for executing checkpoints.
-    </para>
-   </glossdef>
-  </glossentry>
-
   <glossentry id="glossary-checkpoint">
    <glossterm>Checkpoint</glossterm>
    <glossdef>
@@ -244,6 +235,15 @@
    </glossdef>
   </glossentry>
 
+  <glossentry id="glossary-checkpointer">
+   <glossterm>Checkpointer (process)</glossterm>
+   <glossdef>
+    <para>
+     A specialized process responsible for executing checkpoints.
+    </para>
+   </glossdef>
+  </glossentry>
+
   <glossentry>
    <glossterm>Class (archaic)</glossterm>
    <glosssee otherterm="glossary-relation" />
@@ -761,25 +761,6 @@
    </glossdef>
   </glossentry>
 
-  <glossentry id="glossary-logger">
-   <glossterm>Logger (process)</glossterm>
-   <glossdef>
-    <para>
-     If activated, the
-     <glossterm linkend="glossary-logger">Logger</glossterm> process
-     writes information about database events into the current
-     <glossterm linkend="glossary-log-file">log file</glossterm>.
-     When reaching certain time- or
-     volume-dependent criteria, a new log file is created.
-     Also called <firstterm>syslogger</firstterm>.
-    </para>
-    <para>
-     For more information, see
-     <xref linkend="runtime-config-logging"/>.
-    </para>
-   </glossdef>
-  </glossentry>
-
   <glossentry id="glossary-log-record">
    <glossterm>Log Record</glossterm>
     <glossdef>
@@ -803,6 +784,25 @@
    </glossdef>
   </glossentry>
 
+  <glossentry id="glossary-logger">
+   <glossterm>Logger (process)</glossterm>
+   <glossdef>
+    <para>
+     If activated, the
+     <glossterm linkend="glossary-logger">Logger</glossterm> process
+     writes information about database events into the current
+     <glossterm linkend="glossary-log-file">log file</glossterm>.
+     When reaching certain time- or
+     volume-dependent criteria, a new log file is created.
+     Also called <firstterm>syslogger</firstterm>.
+    </para>
+    <para>
+     For more information, see
+     <xref linkend="runtime-config-logging"/>.
+    </para>
+   </glossdef>
+  </glossentry>
+
   <glossentry>
    <glossterm>Master (server)</glossterm>
    <glosssee otherterm="glossary-primary-server" />
@@ -1651,6 +1651,11 @@
    </glossdef>
   </glossentry>
 
+  <glossentry>
+   <glossterm>WAL</glossterm>
+   <glosssee otherterm="glossary-wal" />
+  </glossentry>
+
   <glossentry id="glossary-wal-archiver">
    <glossterm>WAL Archiver (process)</glossterm>
    <glossdef>
@@ -1696,11 +1701,6 @@
    </glossdef>
   </glossentry>
 
-  <glossentry>
-   <glossterm>WAL</glossterm>
-   <glosssee otherterm="glossary-wal" />
-  </glossentry>
-
   <glossentry id="glossary-wal-record">
    <glossterm>WAL Record</glossterm>
    <glossdef>
@@ -1728,8 +1728,8 @@
   <glossdef>
    <para>
     A process that writes <glossterm linkend="glossary-wal-record">WAL records</glossterm>
-    from <glossterm id="linkend-shared-memory">shared memory</glossterm> to
-    <glossterm id="linkend-wal-file">WAL files</glossterm>.
+    from <glossterm linkend="glossary-shared-memory">shared memory</glossterm> to
+    <glossterm linkend="glossary-wal-file">WAL files</glossterm>.
    </para>
    <para>
     For more information, see