Hi, Does anybody know why the planner treats "= ANY(ARRAY(select ...))" differently than "IN(select ...)"? Which one is preferable, when I already have a lot of joins? Thanks, Clemens 2011/5/17 Clemens Eisserer <linuxhippy@xxxxxxxxx>: > Hi, > >>> select .... from t1 left join t2 .... WHERE id IN (select ....) >> >> Does it work as expected with one less join? ÂIf so, try increasing >> join_collapse_limit ... > > That did the trick - thanks a lot. I only had to increase > join_collapse_limit a bit and now get an almost perfect plan. > Instead of hash-joining all the data, the planner generates > nested-loop-joins with index only on the few rows I fetch. > > Using = ANY(array(select... )) also seems to work, I wonder which one > works better. Does ANY(ARRAY(...)) force the optimizer to plan the > subquery seperated from the main query? > > Thanks, Clemens > -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
