On Tue, Nov 15, 2011 at 7:59 PM, Royce Ausburn <royce...@inomial.com> wrote: >> Personally I think some log output, done better, would have been more useful >> for me at the time. At the time I was trying to diagnose an ineffective >> vacuum and postgres' logs weren't giving me any hints about what was wrong. >> I turned to the mailing list and got immediate help, but I felt that ideally >> postgres would be logging something to tell me that some 1 day old >> transactions were preventing auto vacuum from doing its job. Something, >> anything that I could google. Other novices in my situation probably >> wouldn't know to look in the pg_stats* tables, so in retrospect my patch >> isn't really achieving my original goal. >> >> Should we consider taking a logging approach instead? > > Dopey suggestion: > > Instead of logging around vacuum and auto_vacuum, perhaps log transactions > that are open for longer than some (perhaps configurable) time? The default > might be pretty large, say 6 hours. Are there common use cases for txs that > run for longer than 6 hours? Seeing a message such as: > > WARNING: Transaction <X> has been open more than Y. This tx may be holding > locks preventing other txs from operating and may prevent vacuum from > cleaning up deleted rows. > > Would give a pretty clear indication of a problem :)
Well, you could that much just by periodically querying pg_stat_activity. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
