On Wed, Mar 14, 2012 at 08:26:06PM -0400, Tom Lane wrote: > Bruce Momjian <br...@momjian.us> writes: > > Does anyone know how bad the queries will be with only one target? > > Bad. That cycle seems like largely a waste of time. About the only > thing it would do for you is ensure that relpages/reltuples are up to > date, which seems like something we could possibly arrange for during > the data import.
Well, it is also getting us the most common value, which seems useful. > > I did see if vacuumdb --analyze-only was somehow being throttled by the > > vacuum settings, but saw the drive at 100% utilization analying a 36GB > > table on a 24GB RAM server, so it seems I/O bound. > > I think it'd be good to explicitly set vacuum_cost_delay to 0 in the > first pass, in the same way as you are forcing > default_statistics_target, just in case somebody has a nondefault > setting for that. The second pass could probably be allowed to use some > higher delay setting. OK, I have now set vacuum_cost_delay=0 for the first vacuumdb (target=1). -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
