From 343d5c18bf23f98341b510595e3e042e002242cb Mon Sep 17 00:00:00 2001 From: Corey Huinker Date: Sun, 13 Oct 2019 17:57:36 +0000 Subject: [PATCH] add glossary page with sample terms and definitions --- doc/src/sgml/filelist.sgml | 1 + doc/src/sgml/glossary.sgml | 618 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/stylesheet.css | 2 + 3 files changed, 621 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 @@ + diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml new file mode 100644 index 0000000000..016eee2d76 --- /dev/null +++ b/doc/src/sgml/glossary.sgml @@ -0,0 +1,618 @@ + + + + Glossary + + + This is a list of terms and their in the context of PostgreSQL and databases in general. + + + + + Aggregate + + + To combine a collection of data values into a single value, whose value +may not be of the same type as the original values. Aggregate functions combine +multiple rows that share a common set of values into one row, which means that +the only data visible in the values in common, and the aggregates of the +non-common data. + + + + + + Analytic + + + A function whose computed value can reference values found in nearby rows +of the same result set. + + + + + + Atomic + + + In reference to the value of an Attribute or Datum: cannot be broken up +into smaller components. + + + In reference to an operation: An event that cannot be completed in part: +it must either entirely succeed or entirely fail. A series of SQL statements can +be combined into a Transaction, and that transaction is said to be Atomic. + + + + + + Attribute + + + A typed data element found within a Tuple or Relation or Table. + + + + + + Cast + + + A conversion of a Datum from its current data type to another data type. + + + + + + Check Constraint + + + A type of constraint defined on a relation which restricts the values +allowed in one or more Attributes. The check constraint can make reference to +any Attribute in the Relation, but cannot reference other rows of the same +relation or other relations. + + + + + + Column + + + An Attribute found in a Table or View. + + + + + + Commit + + + The act of finalizing a Transaction within the database. + + + + + + Concurrency + + + The concept that multiple independent operations can be happening within +the database at the same time. + + + + + + Constraint + + + A method of restricting the values of data allowed within a Table. + + + + + + Datum + + + The internal representation of a SQL Datatype. + + + + + + Delete + + + A SQL command whose purpose is to remove rows from a given Table or +relation. + + + + + + Foreign Data Wrapper + + + A means of representing data that is not contained in the local database +as if were in local tables. With a Foreign Data Wrapper it is possible to define +a Foreign Server and Foreign Tables. + + + + + + Foreign Key + + + A type of Constraint defined on one or more columns in a Table which requires the +value in those columns to uniquely identify a row in the specified table. + + + + + + Foreign Server + + + A named collection of Foreign Tables which all use the same Foreign Data +Wrapper and have other configured attributes in common. + + + + + + Foreign Table + + + A relation which appears to have Rows and Columns like a regular Table, +but when queried will instead forward the request for data through its Foreign +Data Wrapper, which will return results structured according to the definition +of the Foreign Table. + + + + + + Function + + + Any pre-defined tranformation of data. Many functions are already defined +within PostgreSQL itsel, but can also be user-defined. + + + + + + Grant + + + A SQL command that is used to enable Users or Roles to access specific +objects within the database. + + + + + + Index + + + A relation that contains data derived from a Table (or Relation like a +Materialized View) that stores the data in a way that makes specific values +easier to retrieve. + + + + + + Insert + + + A SQL command used to add new data into a Table. + + + + + + Join + + + A Join is a technique used with Select statements for correlating data in +one Data Set (usually a Table) with another. + TODO + + + + + + Key + + + A Key is a means of identifying a row within a Table or Relation by values +contained within one or more Attributes in that Table. + + + + + + Lock + + + A mechanism for one process temporarily preventing data from being +manipulated by any other process. + TODO + + + + + + Logged + + + A table is considered Logged if changes to the table are send to the WAL +log. By default, all regular tables are logged. A table can be speficied as +unlogged either at creation time or via the ALTER TABLE 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. Temporary tables are +always unlogged. + + + + + + Master + + + When two or more databases are linked via replication, the server that is +considered the authoritative source of information is called the Master. + + + + + + Materialized + + + The act of storing information rather than just the means of accessing the +information. This term is used in Materialized Views meaning that the data +derived from the view is actually stored on disk separate from the sources of +that data. When materialized 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) + + + + + + Materialized View + + + A Relation that is defined in the same way that a View is, but it stores +data in the same way that a Table does. it cannot be modified via INSERT, +UPDATE, or DELETE operations. + + + + + + Null + + + A concept of non-existence that is a central tenet of Relational Database +Theory. It represents the absence of value. + + + + + + Partition + + + A Table that can be queried independently by its own name, but can also be +queried via another table, a partitioend 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 set of tables. + + + A defined boundary used in an Analytic function to identify which +neighboring rows can be considered by the function for this particular row. + + + + + + Primary Key + + + A Unique Index defined on a Table or other Relation that also guarantees +that all of the Attributes within the Primary Key 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 null-capable +attributes. + + + + + + Procedure + + + 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 Functions but are different in that they must be invoked via the CALL +command rather than the SELECT or PERFORM commands, and they are allowed to make +transactional statements like COMMIT and ROLLBACK. + + + + + + Record + + + A data structure that consists of one or more Attributes in a defined +order. + + A single row of a Table or other Relation. + + + + + + + Referential Integrity + + + The means of restricting data in one Relation such that it must have +matching data in another Relation. + + + + + + Relation + + + The generic term for all objects in a database that have a name and a +list of attributes defined in a specific order. Tables, Views, Foreign Tables, +Materialized Views and Indexes are all Relations. + + + + + + Replica + + + A database that is paired with a Master database and is maintaining 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 even that the master becomes unavailable. + + + + + + Revoke + + + A command to reduce access to a named set of database objects for a named +list of users and Roles. + + + + + + Role + + + A collection of access privileges to 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 Users need the same privileges. + + + + + + Rollback + + + A command to undo all of the operations performed since the beginning of a +transaction. + + + + + + Row + + + A tuple or record found within a Relation or a Result Set. This term is +often used interchangably with Record and Tuple. + + + + + + Schema + + + A named collection of database objects organized to facilitate clarity or +security. Most often used like a namespace is used in programming languages. +All objects belong to exactly one schema, most commonly "public", the default +schema. + + + More generically, the term Schema is used to mean all data descriptions +(table definitions, constraints, comments) for a given database. + + + + + + Select + + + The command used to query a database. Normally, SELECTs are not expected +to modify the database in any way, but it is possible that functions invoked +within the query could have side-effects that do modify data. + + + + + + Serializable + + + Database sessions in a transaction defined as SERIALIZABLE 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. + + + + + + Session + + + A connection to the database. + + + A description of the commands that were issued in the life cycle of a +particular connection to the database. + + + + + + Table + + + A collection of tuples (also known as rows or records) having a common data structure (the same number of columns, in the same order, having the same type). A table is the most common form of relation in PostgreSQL. + + + + + + Temporary + + + Temporary tables are tables that exist either for the lifetime of a +Session or a Transaction, 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. + + + + + + Transaction + + + A combination of one or more commands that must act as a single Atomic +command: they all succeed or fail together, and their effects are not visible to +other sessions until the transaction is complete. + + + + + + Trigger + + + A function which can be defined to execute whenever a certain operation +(Insert, Update, or Delete) is applied to that Relation. A trigger executes +within the same transaction as the statement which invoked it, and if the +function fails then the invoking statement also fails. + + + + + + Tuple + + + A collection of Attributes in a fixed order. That order may be defined by +the Table where the Tuple is found, in which case the Tuple is often called a +Row or Record. It may also be defined by the structure of a Result Set. + + + + + + Unique + + + The condition of having no matching values in the same Relation. Most +often used in the concept of Unique Indexes. + + + + + + Unlogged + + + A relation that is unlogged will not have changes reflected in the WAL +log, which would enable those changes to be duplicated on a replica, and also +enables the change to survive a database crash. + + + + + + Update + + + A command used to modify rows that already exist in a specified table. It +cannot create rows nor can it remove rows. + + + + + + User + + + A specific case of a Role that is entitled to access (log into) the +database. + + + + + + User Mapping + + + The translation of user credentials in the local database to credentials +in a remote data system defined by a Foreign Data Wrapper. + + + + + + View + + + A Relation that is defined by a Select 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. + + + + + + Window Function + + + A type of function similar to an aggregate in that can derive its value +from a set of rows in a result set, but still retaining the original source +data. + + + + + diff --git a/doc/src/sgml/stylesheet.css b/doc/src/sgml/stylesheet.css index 1a66c789d5..e51752aca2 100644 --- a/doc/src/sgml/stylesheet.css +++ b/doc/src/sgml/stylesheet.css @@ -101,6 +101,8 @@ var { font-family: monospace; font-style: italic; } /* Konqueror's standard style for ACRONYM is italic. */ acronym { font-style: inherit; } +glossaryterm { font-style: inherit; } + .option { white-space: nowrap; } /* make images not too wide on larger screens */ -- 2.17.1