Thom Brown <[email protected]> wrote:
> Looks good. Do we usually got into fine details such as the name
> of the index? They'll see the index name returned when they
> create the table or add the constraint anyway, and if they missed
> it they only need to do a "\dt tablename" to find out what it was.
Hmmm... Perhaps that is overkill. It seemed like a good idea at
the time, but I'm not inclined to argue about it if it seems too
detailed to you. Revised patch attached.
-Kevin
*** a/doc/src/sgml/ddl.sgml
--- b/doc/src/sgml/ddl.sgml
***************
*** 550,555 **** CREATE TABLE products (
--- 550,560 ----
</indexterm>
<para>
+ Adding a unique constraint will automatically create a unique btree
+ index on the column or group of columns declared for the constraint.
+ </para>
+
+ <para>
In general, a unique constraint is violated when there is more than
one row in the table where the values of all of the
columns included in the constraint are equal.
***************
*** 623,628 **** CREATE TABLE example (
--- 628,638 ----
</para>
<para>
+ Adding a primary key will automatically create a unique btree index
+ on the column or group of columns declared for the primary key.
+ </para>
+
+ <para>
A table can have at most one primary key. (There can be any number
of unique and not-null constraints, which are functionally the same
thing, but only one can be identified as the primary key.)
***************
*** 832,837 **** CREATE TABLE order_items (
--- 842,857 ----
</para>
<para>
+ Since a <command>DELETE</command> of a row from a referenced table
+ or an <command>UPDATE</command> of a referenced column will require
+ a scan of the referencing table for rows matching the old value, it
+ is often a good idea to index the referencing columns. Because it
+ is not always needed, and there are many choices available on how
+ index, declaration of a foreign key constraint does not
+ automatically create an index.
+ </para>
+
+ <para>
More information about updating and deleting data is in <xref
linkend="dml">.
</para>
***************
*** 875,880 **** CREATE TABLE circles (
--- 895,905 ----
See also <link linkend="SQL-CREATETABLE-EXCLUDE"><command>CREATE
TABLE ... CONSTRAINT ... EXCLUDE</></link> for details.
</para>
+
+ <para>
+ Adding an exclusion constraint will automatically create an index
+ of the type specified in the constraint declaration.
+ </para>
</sect2>
</sect1>
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