On Wed, 2009-09-16 at 23:12 -0400, Tom Lane wrote: > Jeff Davis <pg...@j-davis.com> writes: > > On Wed, 2009-09-16 at 21:48 -0400, Tom Lane wrote: > >> Yeah, I was just wondering about that myself. Seems like there would > >> be lots of situations where short exclusive-lock intervals could be > >> tolerated, even though not long ones. > > > But a short-lived exclusive lock can turn into a long-lived exclusive > > lock if there are long-lived transactions ahead of it in the queue. We > > probably don't want to automate anything by default that acquires > > exclusive locks, even for a short time. However, I agree that it's fine > > in many situations if the administrator is choosing it. > > Right, which is why autovacuum can't have anything to do with this.
We already do this and we already solved the problem associated with it. VACUUM tries to grab a conditional lock to shrink the table. We can do the same thing here, just retry the lock for each chunk cleaned. -- Simon Riggs www.2ndQuadrant.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
