Re: Conditional NOTIFY is not implemented - Mailing list pgsql-bugs

I said:
> Changing the rewriter to error out when it couldn't really Do The Right
> Thing seemed like a good idea at the time, but now it seems clear that
> this didn't do anything to enhance the usefulness of the system.  Unless
> someone objects, I'll change it back for 7.2.

Not having seen any objections, I've committed the change.  If you need
a fix in place before 7.2, it's really a trivial change: just replace
the elog calls (there are two) by "return".  See attached patch against
current sources.

            regards, tom lane


*** /home/postgres/pgsql/src/backend/rewrite/rewriteManip.c.orig    Wed Apr 18 16:42:55 2001
--- /home/postgres/pgsql/src/backend/rewrite/rewriteManip.c    Fri Sep  7 16:52:31 2001
***************
*** 592,606 ****

      if (parsetree->commandType == CMD_UTILITY)
      {
-
          /*
!          * 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 (parsetree->utilityStmt && IsA(parsetree->utilityStmt, NotifyStmt))
!             elog(ERROR, "Conditional NOTIFY is not implemented");
          else
              elog(ERROR, "Conditional utility statements are not implemented");
      }
--- 592,612 ----

      if (parsetree->commandType == CMD_UTILITY)
      {
          /*
!          * There's noplace to put the qual on a utility statement.
!          *
!          * 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))
!             return;
          else
              elog(ERROR, "Conditional utility statements are not implemented");
      }
***************
*** 634,648 ****

      if (parsetree->commandType == CMD_UTILITY)
      {
-
          /*
!          * 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 (parsetree->utilityStmt && IsA(parsetree->utilityStmt, NotifyStmt))
!             elog(ERROR, "Conditional NOTIFY is not implemented");
          else
              elog(ERROR, "Conditional utility statements are not implemented");
      }
--- 640,652 ----

      if (parsetree->commandType == CMD_UTILITY)
      {
          /*
!          * There's noplace to put the qual on a utility statement.
           *
!          * See comments in AddQual for motivation.
           */
          if (parsetree->utilityStmt && IsA(parsetree->utilityStmt, NotifyStmt))
!             return;
          else
              elog(ERROR, "Conditional utility statements are not implemented");
      }