Am 23.08.10 12:18, schrieb Scott Marlowe: > On Mon, Aug 23, 2010 at 4:15 AM, Jann Röder <roederja@xxxxxxx> wrote: >> Am 23.08.10 07:52, schrieb Scott Marlowe: >>> Also are a.indexid and b.indexid the same type? >>> >> >> You mean ItemID? Fields of the same name are of the same type - so yes. >> According to the documentation pgsql adds indexes for primary keys >> automatically so (b.itemID, b.indexNumber) is indexed. Or do you think >> adding an extra idnex for b.itemID alone will help? If I understand the >> documentation correctly, pqSQL can use the first column of a >> multi-column index as if it was indexed individually... but maybe I'm >> wrong here. > > It can but that doesn't mean it will. A multi-column index is often > quite a bit bigger than a single column one. > > What happens if you try > > set enable_seqscan=off; > (your query here) > Tried that already. The query plan is exactly the same. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
