summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSimon Riggs <simon@2ndQuadrant.com>2013-06-18 12:10:10 +0100
committerSimon Riggs <simon@2ndQuadrant.com>2013-06-18 12:10:10 +0100
commit0ae1bf8c1be7eccc54792a9c211345f97a11f78e (patch)
tree5ac2bd44a8ebadd9a0d715cc2922b070fd375da2
parent7558c1c00a2195e9de88121e2af5119b609a8600 (diff)
Fix docs on lock level for ALTER TABLE VALIDATE
ALTER TABLE .. VALIDATE CONSTRAINT previously gave incorrect details about lock levels and therefore incomplete reasons to use the option. Initial bug report and fix from Marko Tiikkaja Reworded by me to include comments by Kevin Grittner
-rw-r--r--doc/src/sgml/ref/alter_table.sgml10
1 files changed, 7 insertions, 3 deletions
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index 5437626c3fe..7ee0aa8ca07 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -324,9 +324,13 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="PARAMETER">name</replaceable>
as <literal>NOT VALID</literal>, by scanning the table to ensure there
are no rows for which the constraint is not satisfied.
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>
+ <para>
+ Validation can be a long process on larger tables and currently requires
+ an <literal>ACCESS EXCLUSIVE</literal> lock. The value of separating
+ validation from initial creation is that you can defer validation to less
+ busy times, or can be used to give additional time to correct pre-existing
+ errors while preventing new errors.
</para>
</listitem>
</varlistentry>