On 06/03/2013 11:12 AM, Andres Freund wrote: > On 2013-06-03 11:00:38 -0700, Josh Berkus wrote: >> >>>> Also, locking while it does its work. >>> >>> Eh? >> >> Even if we're doing lazy vacuum, we have to lock a few pages at a time >> of each table. This does result in response time delays on the current >> workload, which can be quite bad if it's a highly contended table already. > > We don't really lock more pages at a time than normal DML does. 1 heap > page at a time, possibly several index pages at once.
Really? I though vacuum held onto its locks until it reached vacuum_cost. If it doesn't, then maybe we should adjust the default for vacuum_cost_limit upwards. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
