2006/12/5, Scott Marlowe <smarlowe@xxxxxxxxxxxxxxxxx>:
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.
8.1.something
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.
We frequently run into the same basic RDBMS benchmarking problem: basically any database can be fastest in a given context, depending on how the query is expressed and what it does. Cheers, t.n.a.
