On Thu, Oct 25, 2007 at 03:54:28PM -0400, Andrew Dunstan wrote: > Simon Riggs wrote: > >On Thu, 2007-10-25 at 13:51 -0400, Andrew Dunstan wrote: > >>Michael Paesold wrote: > >> > >>>In the previous discussion, Simon and me agreed that schema > >>>changes should not happen on a regular basis on production > >>>systems. > >>> > >>>Shouldn't we rather support the regular usage pattern instead of > >>>the uncommon one? Users doing a lot of schema changes are the > >>>ones who should have to work around issues, not those using a > >>>DBMS sanely. No? > >>> > >>Unfortunately, doing lots of schema changes is a very common > >>phenomenon. It makes me uncomfortable too, but saying that those > >>who do it have to work around issues isn't acceptable IMNSHO - > >>it's far too widely done. > > > >We didn't agree that DDL was uncommon, we agreed that running DDL > >was more important than running an auto VACUUM. DDL runs very > >quickly, unless blocked, though holds up everybody else. So you > >must run it at pre-planned windows. VACUUMs can run at any time, so > >a autoVACUUM shouldn't be allowed to prevent DDL from running. The > >queuing DDL makes other requests queue behind it, even ones that > >would normally have been able to execute at same time as the > >VACUUM. > > > >Anyway, we covered all this before. I started off saying we > >shouldn't do this and Heikki and Michael came up with convincing > >arguments, for me, so now I think we should allow autovacuums to be > >cancelled. > > Perhaps I misunderstood, or have been mistunderstood :-) - I am > actually agreeing that autovac should not block DDL.
+1 here for having autovacuum not block DDL :) Cheers, David (for what it's worth) -- David Fetter <[EMAIL PROTECTED]> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: [EMAIL PROTECTED] Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
