diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/catalogs.sgml | 3 | ||||
| -rw-r--r-- | doc/src/sgml/ref/alter_table.sgml | 48 |
2 files changed, 30 insertions, 21 deletions
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index 8504555bac9..24d7d98722a 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -1898,7 +1898,8 @@ <entry><structfield>convalidated</structfield></entry> <entry><type>bool</type></entry> <entry></entry> - <entry>Has the constraint been validated? Can only be false for foreign keys</entry> + <entry>Has the constraint been validated? + Currently, can only be false for foreign keys</entry> </row> <row> diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index 4e02438483b..01d3105bf6c 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -42,9 +42,8 @@ ALTER TABLE <replaceable class="PARAMETER">name</replaceable> ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> SET ( <replaceable class="PARAMETER">attribute_option</replaceable> = <replaceable class="PARAMETER">value</replaceable> [, ... ] ) ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> RESET ( <replaceable class="PARAMETER">attribute_option</replaceable> [, ... ] ) ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN } - ADD <replaceable class="PARAMETER">table_constraint</replaceable> - ADD <replaceable class="PARAMETER">table_constraint_using_index</replaceable> ADD <replaceable class="PARAMETER">table_constraint</replaceable> [ NOT VALID ] + ADD <replaceable class="PARAMETER">table_constraint_using_index</replaceable> VALIDATE CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable> DROP CONSTRAINT [ IF EXISTS ] <replaceable class="PARAMETER">constraint_name</replaceable> [ RESTRICT | CASCADE ] DISABLE TRIGGER [ <replaceable class="PARAMETER">trigger_name</replaceable> | ALL | USER ] @@ -235,27 +234,21 @@ ALTER TABLE <replaceable class="PARAMETER">name</replaceable> </varlistentry> <varlistentry> - <term><literal>ADD <replaceable class="PARAMETER">table_constraint</replaceable> - [ NOT VALID ]</literal></term> + <term><literal>ADD <replaceable class="PARAMETER">table_constraint</replaceable> [ NOT VALID ]</literal></term> <listitem> <para> This form adds a new constraint to a table using the same syntax as - <xref linkend="SQL-CREATETABLE">. Newly added foreign key constraints can - also be defined as <literal>NOT VALID</literal> to avoid the - potentially lengthy initial check that must otherwise be performed. - Constraint checks are skipped at create table time, so - <xref linkend="SQL-CREATETABLE"> does not contain this option. - </para> - </listitem> - </varlistentry> - - <varlistentry> - <term><literal>VALIDATE CONSTRAINT</literal></term> - <listitem> - <para> - This form validates a foreign key constraint that was previously created - as <literal>NOT VALID</literal>. Constraints already marked valid do not - cause an error response. + <xref linkend="SQL-CREATETABLE">, plus the option <literal>NOT + VALID</literal>, which is currently only allowed for foreign key + constraints. + If the constraint is marked <literal>NOT VALID</literal>, the + potentially-lengthy initial check to verify that all rows in the table + satisfy the constraint is skipped. The constraint will still be + enforced against subsequent inserts or updates (that is, they'll fail + unless there is a matching row in the referenced table). But the + database will not assume that the constraint holds for all rows in + the table, until it is validated by using the <literal>VALIDATE + CONSTRAINT</literal> option. </para> </listitem> </varlistentry> @@ -312,6 +305,21 @@ ALTER TABLE <replaceable class="PARAMETER">name</replaceable> </varlistentry> <varlistentry> + <term><literal>VALIDATE CONSTRAINT</literal></term> + <listitem> + <para> + This form validates a foreign key constraint that was previously created + as <literal>NOT VALID</literal>, by scanning the table to ensure there + are no unmatched rows. Nothing happens if the constraint is + already marked valid. + The value of separating validation from initial creation of the + constraint is that validation requires a lesser lock on the table + than constraint creation does. + </para> + </listitem> + </varlistentry> + + <varlistentry> <term><literal>DROP CONSTRAINT [ IF EXISTS ]</literal></term> <listitem> <para> |