database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-28 23:42:10 +03:00
Code Activity

Rework parsing of ConstraintAttributeSpec to improve NOT VALID handling.

Browse Source 
The initial commit of the ALTER TABLE ADD FOREIGN KEY NOT VALID feature
failed to support labeling such constraints as deferrable.  The best fix
for this seems to be to fold NOT VALID into ConstraintAttributeSpec.
That's a bit more general than the documented syntax, but it allows
better-targeted syntax error messages.

In addition, do some mostly-but-not-entirely-cosmetic code review for
the whole NOT VALID patch.
This commit is contained in:
Tom Lane
2011-06-15 19:05:11 -04:00
parent e3df3572f6
commit e1ccaff6ee
9 changed files with 181 additions and 121 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
doc/src/sgml/catalogs.sgml
View File

@ -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>

48
doc/src/sgml/ref/alter_table.sgml
View File

@ -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>
@ -311,6 +304,21 @@ ALTER TABLE <replaceable class="PARAMETER">name</replaceable>
</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>, 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>