On Tue, 2006-12-05 at 16:32, Tomi N/A wrote: > One type of query does come to mind, now that I think about it. > pgsql has trouble handling queries like > SELECT * FROM t0 WHERE t0.id_t1 IN (SELECT t1.id FROM t1 WHERE...)
> When the subselect returns a lot of results, pgsql really takes it's time. Just wondering what version of pgsql you were using, as the in() performance has been greatly improved in the newer versions. What I noticed was that PostgreSQL was better under parallel load than MSSQL server was. Our pgsql 7.2 server would routinely outrun the MSSQL server (This was like 3 years ago) when they were both moderately loaded. Of course, we didn't run a lot of where in () queries on the pgsql server, we re-worked them to favor postgresql's query planner of the time. ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
