Scott Marlowe <scott.marlowe@xxxxxxxxx> writes: > I extracted all the data like so: > select * into dba.pp_test_wide from original table; > and get this query plan from explain analyze: > http://explain.depesz.com/s/EPx which takes 20 minutes to run. > If I extract it this way: > select tree_sortkey, product_name, deleted_at into db.pp_test_3col > from original table; > I get this plan: http://explain.depesz.com/s/gru which gets a > materialize in it, and suddenly takes 106 ms. There's no reason why suppressing some unrelated columns would change the rowcount estimates, but those two plans show different rowcount estimates. I suspect the *actual* reason for the plan change was that autovacuum had had a chance to update statistics for the one table, and not yet for the other. Please do a manual ANALYZE on both tables and see if there's still a plan difference. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
