Re: pgsql: Fix documentation template for CREATE TRIGGER.

On Sun, Jun 22, 2014 at 12:19:49PM -0700, Jeff Davis wrote:
> On Sat, 2014-06-21 at 14:21 +0000, Kevin Grittner wrote:
> > Fix documentation template for CREATE TRIGGER.
> >
> > By using curly braces, the template had specified that one of
> > "NOT DEFERRABLE", "INITIALLY IMMEDIATE", or "INITIALLY DEFERRED"
> > was required on any CREATE TRIGGER statement, which is not
> > accurate.  Change to square brackets makes that optional.
> >
> > Backpatch to 9.1, where the error was introduced.
>
> It still doesn't look quite right to me. The new form:
>
> [ NOT DEFERRABLE | [ DEFERRABLE ] { INITIALLY IMMEDIATE | INITIALLY
> DEFERRED } ]
>
> says that, if DEFERRABLE is specified, then INITIALLY IMMEDIATE or
> INITIALLY DEFERRED is required. But the following is accepted by the
> server:
>
>   create constraint trigger mytrigger
>     after insert on dummy_table deferrable
>     for each row execute procedure dummy_trigger();
>
> (Although the standard doesn't seem to have deferrable triggers, that
> does seem to match the deferrable constraint syntax that is in the
> spec.)
>
> For that matter, the following is also accepted by the server:
>
>   create constraint trigger mytrigger
>     after insert on dummy_table initially deferred deferrable
>     for each row execute procedure dummy_trigger();
>
> That case may be a bug; and regardless I don't think we want to
> document/encourage specifying them in that order. But the first case
> seems reasonable to me.

I agree with both statements so I have applied the attached doc patch to
head.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + Everyone has their own god. +