Re: Patch: plan invalidation vs stored procedures

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@commandprompt.com>
Cc: Dimitri Fontaine <dfontaine@hi-media.com>, Bruce Momjian <bruce@momjian.us>, Joshua Drake <jd@commandprompt.com>, Gregory Stark <stark@enterprisedb.com>, Hannu Krosing <hannu@2ndQuadrant.com>, Asko Oja <ascoja@gmail.com>, Pavel Stehule <pavel.stehule@gmail.com>, pgsql-hackers@postgresql.org, Andrew Dunstan <andrew@dunslane.net>, David Fetter <david@fetter.org>, Martin Pihlak <martin.pihlak@gmail.com>
Date: 2008-08-19T20:56:04Z
Lists: pgsql-hackers
Alvaro Herrera <alvherre@commandprompt.com> writes:
> The actual criterion is not really "new user-visible feature" versus
> "bug fix".  It's more an attempt at measuring how large a potential
> impact the change has.  The patch I saw was introducing a whole new
> message type to go through the shared invalidation queue, which is not
> something to be taken lightly (consider that there are three message
> types of messages currently.)

I hadn't read it yet, but that makes it wrong already.  There's no need
for any new inval traffic --- the existing syscache inval messages on
pg_proc entries should serve fine.

More generally, if we are to try to invalidate on the strength of
pg_proc changes, what of other DDL changes?  Operators, operator
classes, maybe?  How about renaming a schema?  I would like to see a
line drawn between things we find worth trying to track and things we
don't.  If there is no such line, we're going to need a patch a lot
larger than this one.

			regards, tom lane