Re: Patch: plan invalidation vs stored procedures
Zdenek Kotala <zdenek.kotala@sun.com>
From: Zdenek Kotala <Zdenek.Kotala@Sun.COM>
To: David Fetter <david@fetter.org>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Hannu Krosing <hannu@2ndQuadrant.com>, Robert Haas <robertmhaas@gmail.com>, Dimitri Fontaine <dfontaine@hi-media.com>, pgsql-hackers@postgresql.org
Date: 2008-08-20T14:31:13Z
Lists: pgsql-hackers
David Fetter napsal(a): > On Tue, Aug 19, 2008 at 09:50:53PM -0400, Tom Lane wrote: >> David Fetter <david@fetter.org> writes: >>> On Tue, Aug 19, 2008 at 07:45:16PM -0400, Tom Lane wrote: >>>> FWIW, given that there will probably always be corner cases. I can >>>> see the attraction in Simon's suggestion of providing a way to >>>> manually issue a system-wide forced plan flush. >>> Would that require a system-wide plan cache to implement? >> No, just a function that can issue a suitable sinval message. >> >> plancache.c would already respond in the desired way to a relcache inval >> message with OID = 0, though likely it'll be cleaner to invent an sinval >> message type specifically for the purpose. >> >> One thing to think about is whether the flush should be truly >> system-wide or just database-wide. I can see a lot more uses for the >> latter than the former --- I don't think there's a reason for cached >> plans to depend on any contents of the shared catalogs. > > They might during an on-line upgrade. > At this moment we have offline catalog upgrade. On-line old catalog processing is nice idea but amount of work and impact is too high to do it. Catalog is usually small and its offline upgrade is fast. Zdenek