Mark Davidson <mark@xxxxxxxxxxx> wrote: > CONSTRAINT data_area_pkey PRIMARY KEY (data_id , area_id ), So the only index on this 250 million row table starts with the ID of the point, but you are joining to it by the ID of the area. That's requires a sequential scan of all 250 million rows. Switch the order of the columns in the primary key, add a unique index with the columns switched, or add an index on just the area ID. Perhaps you thought that the foreign key constraints would create indexes? (They don't.) -- Kevin Grittner EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
