On 2015/11/12 4:26, Robert Haas wrote: > On Wed, Nov 11, 2015 at 12:59 PM, Pavel Stehule <pavel.steh...@gmail.com> > wrote: >> I have a first query >> >> I looked on EXPLAIN ANALYZE output and the numbers of filtered rows are >> differen > > Hmm, I see I was right about people finding more bugs once this was > committed. That didn't take long.
I encountered one more odd behavior: postgres=# EXPLAIN ANALYZE SELECT abalance FROM pgbench_accounts WHERE aid = 23466; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------- Gather (cost=1000.00..65207.88 rows=1 width=4) (actual time=17450.595..17451.151 rows=1 loops=1) Number of Workers: 4 -> Parallel Seq Scan on pgbench_accounts (cost=0.00..64207.78 rows=1 width=4) (actual time=55.934..157001.134 rows=2 loops=1) Filter: (aid = 23466) Rows Removed by Filter: 18047484 Planning time: 0.198 ms Execution time: 17453.565 ms (7 rows) The #rows removed here is almost twice the number of rows in the table (10m). Also, the #rows selected shown is 2 for Parallel Seq Scan whereas only 1 row is selected. Thanks, Amit -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers