From: Dimitri Fontaine <dimitri@2ndQuadrant.fr>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: Event Triggers: adding information
Organization: 2ndQuadrant
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User-Mail-Address: dimitri@2ndQuadrant.fr
Date: Thu, 24 Jan 2013 10:35:41 +0100
In-Reply-To: 
 <CA+Tgmobn7g04hpybaHoDFGzeqE_nfRwYgHWk_5RoA+k2frG1pg@mail.gmail.com>
	(Robert Haas's message of "Tue, 22 Jan 2013 22:01:43 -0500")
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Robert Haas <robertmhaas@gmail.com> writes:
> Or maybe we should just silently ignore failures to look up the event
> trigger.  That might be better, because the DBA could always do:
>
> DROP FUNCTION myeventtrgfn() CASCADE;
>
> ...and it would be undesirable for other sessions to error out in that
> case due to SnapshotNow effects.

What about taking a lock on the functions we decide we will need to be
running, maybe a ShareUpdateExclusiveLock, so that the function can not
disappear under us from concurrent activity?

Note to self, most probably using:
	LockRelationOid(fnoid, ShareUpdateExclusiveLock);

After all, we might be right not to optimize for DDL concurrency=E2=80=A6

Regards,
--=20
Dimitri Fontaine
http://2ndQuadrant.fr     PostgreSQL : Expertise, Formation et Support


--=20
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