decibel <decibel@xxxxxxxxxxx> writes: > On Aug 19, 2009, at 7:45 PM, Jaime Casanova wrote: >> AFAIUI, work_mem is used for some operations (sort, hash, etc) for >> avoiding the use of temp files on disk... >> >> In a client server i'm monitoring (pg 8.3.7, 32GB of ram) work_mem is >> set to 8MB, however i'm seeing a lot of temp files (>30000 in 4 hours) >> with small sizes (ie: 2021520 obviously lower than 8MB). so, why? >> maybe we use work_mem until we find isn't enough and we send just the >> difference to a temp file? >> >> i'm not thinking in raising work_mem until i understand this well, >> what's the point if we still create temp files that could fit in >> work_mem... > Are you using temp tables? Those end up in pgsql_tmp as well. Uh, no, they don't. It might be useful to turn on trace_sort to see if the small files are coming from sorts. If they're from hashes I'm afraid there's no handy instrumentation ... regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
