> > While this is not your questions, I still noticed you seem to be on 8.3 - > it might be a bit faster to use GROUP BY instead of DISTINCT. It didn't do a big difference, I already tried that before for this query. Anyway, as you said, it's not the query having problems :) > Your effective_cache_size is really small for the system you seem to have - > its the size of IO caching your os is doing and uses no resources itself. > And 800MB of that on a system with that amount of data seems a bit unlikely > ;-) > > Using `free` you can see the amount of io caching your OS is doing atm. in > the 'cached' column. > > That possibly might tip some plans in a direction you prefer. > > What kind of machine are you running this on? I played with this parameter too, and it didn't influence the plan. Anyway, the doc says it's the OS cache available for one query, and there may be a lot of insert queries at the same time, so I chose to be conservative with this value. I tried it with 8GB too, the plans were the same. The OS cache is around 8-10GB by the way. The machine is a dell PE2900, with 6 disks dedicated to this database (raid 10 config) -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
