Excerpts from Narasimha Murthy-VRFX87's message of jue may 20 02:47:21 -0400 2010: > Hi Alvaro Herrera, > > Since, my original plan was to run the auto-vacuum daily EXACTLY at 5 am, I > wanted to know which seconds of a minute. My query in other word was, if I > set autovacuum_naptime to 1 hr, which minute of an hour the auto-vacuum runs > (oth min, 15th min or something else).
Yeah, you have no way to be know. I guess you could turn autovacuum off in postgresql.conf all day, and exactly at 5am you have a cron job that edits postgresql.conf and reloads Postgres. This would start up autovacuum, which would then continue with the regular schedule. This is hardly ideal; there were plans to improve on this by having an autovacuum schedule, but I think the demand for this feature has decreased considerable, so I haven't given it any minute's thought. > From the clarification given by the you and other community members, I now > understood that autovacuum is designed to run frequently in the background, > not designed to run once a day at a specific time. Due to this design intent, > autovacuum_naptime is set to 1 min by default and autovacuum runs > lazy/plain/standard vacuum commands (so that Vacuum can run concurrently with > other normal DB operations). Correct. -- -- Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
