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Revert treatment of NOTIFY in rules to its pre-7.1 behavior: notify will 

occur unconditionally, even if the rule should otherwise execute
conditionally.  This is more useful than giving an error, even though it's
not truly the correct behavior.  Per today's pghackers discussion.
This commit is contained in:
Tom Lane 2001-09-07 20:52:31 +00:00
parent 8c55728295
commit 17c03b30b0
2 changed files with 30 additions and 12 deletions
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16
doc/src/sgml/ref/create_rule.sgml
View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_rule.sgml,v 1.25 2001/09/03 12:57:49 petere Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_rule.sgml,v 1.26 2001/09/07 20:52:30 tgl Exp $
Postgres documentation
-->
@ -249,6 +249,20 @@ SELECT * FROM emp;
</programlisting></para>
</example>
</para>
<para>
Presently, if a rule contains a NOTIFY query, the NOTIFY will be executed
unconditionally --- that is, the NOTIFY will be issued even if there are
not any rows that the rule should apply to. For example, in
<programlisting>
CREATE RULE notify_me AS ON UPDATE TO mytable DO NOTIFY mytable;
UPDATE mytable SET name = 'foo' WHERE id = 42;
</programlisting>
one NOTIFY event will be sent during the UPDATE, whether or not there
are any rows with id = 42. This is an implementation restriction that
may be fixed in future releases.
</para>
</refsect2>
</refsect1>

26
src/backend/rewrite/rewriteManip.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteManip.c,v 1.57 2001/04/18 20:42:55 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteManip.c,v 1.58 2001/09/07 20:52:31 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -592,15 +592,21 @@ AddQual(Query *parsetree, Node *qual)
if (parsetree->commandType == CMD_UTILITY)
{
/*
* Noplace to put the qual on a utility statement.
* There's noplace to put the qual on a utility statement.
*
* For now, we expect utility stmt to be a NOTIFY, so give a specific
* error message for that case.
* If it's a NOTIFY, silently ignore the qual; this means that the
* NOTIFY will execute, whether or not there are any qualifying rows.
* While clearly wrong, this is much more useful than refusing to
* execute the rule at all, and extra NOTIFY events are harmless for
* typical uses of NOTIFY.
*
* If it isn't a NOTIFY, error out, since unconditional execution
* of other utility stmts is unlikely to be wanted. (This case is
* not currently allowed anyway, but keep the test for safety.)
*/
if (parsetree->utilityStmt && IsA(parsetree->utilityStmt, NotifyStmt))
elog(ERROR, "Conditional NOTIFY is not implemented");
return;
else
elog(ERROR, "Conditional utility statements are not implemented");
}
@ -634,15 +640,13 @@ AddHavingQual(Query *parsetree, Node *havingQual)
if (parsetree->commandType == CMD_UTILITY)
{
/*
* Noplace to put the qual on a utility statement.
* There's noplace to put the qual on a utility statement.
*
* For now, we expect utility stmt to be a NOTIFY, so give a specific
* error message for that case.
* See comments in AddQual for motivation.
*/
if (parsetree->utilityStmt && IsA(parsetree->utilityStmt, NotifyStmt))
elog(ERROR, "Conditional NOTIFY is not implemented");
return;
else
elog(ERROR, "Conditional utility statements are not implemented");
}