Dimitri Fontaine wrote: > Jan Wieck <janwi...@yahoo.com> writes: > > Use this lmgr feature inside count_nondeletable_pages() of vacuumlazy.c to > > periodically check, if there is a conflicting lock request waiting. If not, > > keep going. If there is a waiter, truncate the relation to the point checked > > thus far, release the AccessExclusiveLock, then loop back to where we > > acquire this lock in the first place and continue checking/truncating. > > I think that maybe we could just bail out after releasing the > AccessExclusiveLock and trust autovacuum to get back to truncating that > relation later.
That doesn't work, because the truncating code is not reached unless vacuuming actually took place. So if you interrupt it, it will just not get called again later. Maybe we could have autovacuum somehow invoke that separately, but that would require that the fact that truncation was aborted is kept track of somewhere. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
