On Dec 2, 2007 7:35 AM, Mindaugas <ml@xxxxxxxxxxx> wrote: > I'd like this query to respond under a specific time limit. 5s now is OK but 50s later for 10000 rows is too slow. > > Also off list I was pointed out about covering indexes in MySQL. But they are not supported in PostgreSQL, aren't they? The PostgreSQL architecture does not allow that...some of the MVCC info is stored in the tuple. An all index access strategy would only help anyways if all the information being looked up was in the index...this probably isn't practical in really big table anyways (I think said feature is overrated). What would help, at least temporarily, would be to cluster the table on your index so at least your lookups would have some locality. Just be aware that cluster is a one shot deal...if there are changes to the table it will gradually fall out of order. Otherwise it would be an ordered table, which is what everyone wants...some of the big commercial databases have this. In any case, you should still at least post an explain analyze to make sure something funky isn't going on. Barring that, I would be looking at some type of caching to optimize around the problem...perhaps look at the table design? merlin ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
