Dne 5 Listopad 2014, 18:10, Tom Lane napsal(a): > "Tomas Vondra" <t...@fuzzy.cz> writes: >> Dne 5 Listopad 2014, 17:31, R??my-Christophe Schermesser napsal(a): >>> We have 2 instances of PG, one in 9.1.1 and 9.1.14. They have the same >>> data, schema, PG configuration, and are almost identical machines, same >>> number of cores and memory, but different cloud provider. The data was >>> transferred with a pg_dump/pg_restore. We ran VACUUM ANALYSE, ANALYSE, >>> and >>> REINDEX on both machines. > >> Well, the first observation is that the queries produce different >> results: > > Yeah. Another reason to not believe that the databases contain identical > data is here: > >>> -> Seq Scan on andalertsmatch am (cost=0.00..71287.87 >>> rows=1064987 width=52) (actual time=0.000..1680.077 rows=1064987 >>> loops=1) > >>> -> Index Scan using andalertsmatch_a_mid_idx on andalertsmatch >>> am >>> (cost=0.00..180798.61 rows=1173762 width=52) (actual >>> time=0.015..875294.427 rows=1826118122 loops=1) > > For some reason there's over 1000 times more rows in andalertsmatch in > the 9.1.14 installation. I'm betting on a foulup somewhere in the data > dump/restore process.
I'd bet that's mostly due to rescans in the merge join ... Tomas -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
