git.postgresql.org Git - postgresql.git/commitdiff

diff --git a/doc/src/sgml/ref/set_constraints.sgml b/doc/src/sgml/ref/set_constraints.sgml

index e03910e2529b4d9d8256f99d6eb711cc0f61171e..94c2ecabc72e9a6c59c6b43bba84ae64bf9d8d3d 100644 (file)

--- a/doc/src/sgml/ref/set_constraints.sgml

+++ b/doc/src/sgml/ref/set_constraints.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/ref/set_constraints.sgml,v 1.17 2009年07月29日 20:56:17 tgl Exp $ -->

+<!-- $PostgreSQL: pgsql/doc/src/sgml/ref/set_constraints.sgml,v 1.18 2010年01月18日 00:32:21 tgl Exp $ -->

<refentry id="SQL-SET-CONSTRAINTS">

<refmeta>

<refentrytitle id="SQL-SET-CONSTRAINTS-title">SET CONSTRAINTS</refentrytitle>

<refnamediv>

<refname>SET CONSTRAINTS</refname>

- <refpurpose>set constraint checking modes for the current transaction</refpurpose>

+ <refpurpose>set constraint check timing for the current transaction</refpurpose>

</refnamediv>

<indexterm zone="sql-set-constraints">

<para>

<command>SET CONSTRAINTS</command> with a list of constraint names changes

- the mode of just those constraints (which must all be deferrable). The

+ the mode of just those constraints (which must all be deferrable). Each

+ constraint name can be schema-qualified. The

current schema search path is used to find the first matching name if

no schema name is specified. <command>SET CONSTRAINTS ALL</command>

changes the mode of all deferrable constraints.

</para>

<para>

- Currently, only <literal>UNIQUE</>, <literal>PRIMARY KEY</>, and

- <literal>REFERENCES</> (foreign key) constraints are affected by this

- setting. <literal>NOT NULL</> and <literal>CHECK</> constraints are

+ Currently, only <literal>UNIQUE</>, <literal>PRIMARY KEY</>,

+ <literal>REFERENCES</> (foreign key), and <literal>EXCLUDE</>

+ constraints are affected by this setting.

+ <literal>NOT NULL</> and <literal>CHECK</> constraints are

always checked immediately when a row is inserted or modified

(<emphasis>not</> at the end of the statement).

- Uniqueness constraints that have not been declared <literal>DEFERRABLE</>

- are also checked immediately.

+ Uniqueness and exclusion constraints that have not been declared

+ <literal>DEFERRABLE</> are also checked immediately.

</para>

<para>

<refsect1>

<title>Notes</title>

+ <para>

+ Because <productname>PostgreSQL</productname> does not require constraint

+ names to be unique within a schema (but only per-table), it is possible

+ that there is more than one match for a specified constraint name.

+ In this case <command>SET CONSTRAINTS</command> will act on all matches.

+ For a non-schema-qualified name, once a match or matches have been found in

+ some schema in the search path, schemas appearing later in the path are not

+ searched.

+ </para>

+

<para>

This command only alters the behavior of constraints within the

current transaction. Thus, if you execute this command outside of a

<para>

This command complies with the behavior defined in the SQL

standard, except for the limitation that, in

- <productname>PostgreSQL</productname>, it only applies to

- foreign-key and uniqueness constraints.

+ <productname>PostgreSQL</productname>, it does not apply to

+ <literal>NOT NULL</> and <literal>CHECK</> constraints.

+ Also, <productname>PostgreSQL</productname> checks non-deferrable

+ uniqueness constraints immediately, not at end of statement as the

+ standard would suggest.

</para>

</refsect1>