On 10/31/2012 05:55 AM, Vincenzo Melandri wrote:
on People: CREATE UNIQUE INDEX people_pkey ON people USING btree (key1, key2) CREATE INDEX people_pkey_hash_loc ON people USING hash (key1); CREATE INDEX people_pkey_hash_id ON people USING hash (key2);
I can't say why it would ignore the first index in this particular JOIN, but you might as well discard both of those hash indexes. Also, people_pkey_hash_loc is basically pointless anyway, as the database can use the first column in a multi-column index as if it were a single column index.
I *can* ask you why you're using HASH indexes, though. They're not WAL logged, so they can't be replicated, and they're also not crash safe.
-- Shaun Thomas OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604 312-444-8534 sthomas@xxxxxxxxxxxxxxxx ______________________________________________ See http://www.peak6.com/email_disclaimer/ for terms and conditions related to this email -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
