diff options
| -rw-r--r-- | doc/src/sgml/ref/select.sgml | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 9044adfa8c8..444b72cebe5 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.83 2005/04/08 00:59:58 neilc Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/select.sgml,v 1.84 2005/04/22 04:20:44 momjian Exp $ PostgreSQL documentation --> @@ -830,11 +830,13 @@ FOR UPDATE [ OF <replaceable class="parameter">table_name</replaceable> [, ...] </para> <para> - <literal>FOR UPDATE</literal> may appear before - <literal>LIMIT</literal> for compatibility with - <productname>PostgreSQL</productname> versions before 7.3. It - effectively executes after <literal>LIMIT</literal>, however, and - so that is the recommended place to write it. + It is possible for a <command>SELECT</> command using both + <literal>LIMIT</literal> and <literal>FOR UPDATE</literal> + clauses to return fewer rows than specified by <literal>LIMIT</literal>. + This is because <literal>LIMIT</> selects a number of rows, + but might then block requesting a <literal>FOR UPDATE</literal> lock. + Once the <literal>SELECT</> unblocks, the query qualifiation might not + be met and the row not be returned by <literal>SELECT</>. </para> </refsect2> </refsect1> |