Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and
Jim Nasby <jnasby@pervasive.com>
From: "Jim C. Nasby" <jnasby@pervasive.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Bruce Momjian <pgman@candle.pha.pa.us>, Andrew Dunstan <andrew@dunslane.net>, simon@2ndquadrant.com, kleptog@svana.org, gsstark@mit.edu, pg@rbt.ca, zhouqq@cs.toronto.edu, pgsql-hackers@postgresql.org
Date: 2006-01-03T16:43:25Z
Lists: pgsql-hackers
On Tue, Jan 03, 2006 at 11:26:51AM -0500, Tom Lane wrote: > "Jim C. Nasby" <jnasby@pervasive.com> writes: > > Dumb question: if the ALTER is done inside a transaction, and then > > reverted at the end of the transaction, does that mean that no other > > transactions would have those permissions? I think the general use-case > > is that you only one the session doing the ALTER to be able to use these > > special modes, not anyone else who happens to be hitting the table at > > that time... > > Such an ALTER would certainly require exclusive lock on the table, > so I'm not sure that I see much use-case for doing it like that. > You'd want to do the ALTER and commit so as not to lock other people > out of the table entirely while doing the bulk data-pushing. Maybe this just isn't clear, but would EXCLUSIVE block writes from all other sessions then? The post I replied to mentioned that the ALTER would affect all backends is why I'm wondering... -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461