From b85ccf59ad0575e5040b17bbed5d2e152217df47 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <laurenz.albe@cybertec.at>
Date: Fri, 19 Jan 2024 11:37:32 +0100
Subject: [PATCH v3] Doc: All relations share a namespace

This was already documented in the CREATE INDEX reference,
but not in the introductory "Data Definition" chapter.
Also, document that the index that implements a constraint
has the same name as the constraint.

Author: Laurenz Albe
Reviewed-by: Jian He, Peter Eisentraut, David G. Johnston
Discussion: https://postgr.es/m/CACJufxFG682tYcP9aH_F-jrqq5End8MHZR77zcp1%3DDUrEsSu1Q%40mail.gmail.com
---
 doc/src/sgml/ddl.sgml              | 6 +++++-
 doc/src/sgml/ref/create_table.sgml | 9 +++++----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4044f0908f..13831667fe 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -3001,7 +3001,11 @@ SELECT * FROM information WHERE group_id = 2 FOR UPDATE;
   <para>
    A database contains one or more named <firstterm>schemas</firstterm>, which
    in turn contain tables.  Schemas also contain other kinds of named
-   objects, including data types, functions, and operators.  The same
+   objects, including data types, functions, and operators.  Within one schema,
+   two objects of the same type cannot have the same name.  All relations
+   (tables, sequences, indexes, views, materialized views, and foreign tables)
+   share one name space, so they need to have different names if they are in
+   a single schema.  The same
    object name can be used in different schemas without conflict; for
    example, both <literal>schema1</literal> and <literal>myschema</literal> can
    contain tables named <literal>mytable</literal>.  Unlike databases,
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index e04a0692c4..e334b17672 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1001,7 +1001,8 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
 
      <para>
       Adding a unique constraint will automatically create a unique btree
-      index on the column or group of columns used in the constraint.
+      index on the column or group of columns used in the constraint.  That
+      index has the same name as the unique constraint.
      </para>
 
      <para>
@@ -1054,7 +1055,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
      <para>
       Adding a <literal>PRIMARY KEY</literal> constraint will automatically
       create a unique btree index on the column or group of columns used in the
-      constraint.
+      constraint.  That index has the same name as the primary key constraint.
      </para>
 
      <para>
@@ -1091,8 +1092,8 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
 
      <para>
       Exclusion constraints are implemented using
-      an index, so each specified operator must be associated with an
-      appropriate operator class
+      an index that has the same name as the constraint, so each specified
+      operator must be associated with an appropriate operator class
       (see <xref linkend="indexes-opclass"/>) for the index access
       method <replaceable>index_method</replaceable>.
       The operators are required to be commutative.
-- 
2.43.0