-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 08/26/2013 02:33 PM, Rafael Martinez wrote: [............] > The SQL statement is: > > SELECT firstname || ' ' || lastname AS Name FROM Person R WHERE > R.gender like 'F' AND 19 < (SELECT COUNT(DISTINCT filmId) FROM > FilmParticipation F WHERE F.partType = 'director' AND F.personId = > R.personId ) AND NOT EXISTS ( SELECT * FROM > FilmParticipation D WHERE D.partType = 'director' AND D.personId > = R.personId AND NOT EXISTS ( SELECT * FROM FilmParticipation > C WHERE C.partType = 'cast' AND C.filmId = D.filmId AND > C.personId = D.personId ) ) ; > > [.............] > > We can see that the query plan is very different between versions > and that 9.2 is really wrong with the number of rows involved. Why > is 9.2 taking so wrong about the number of rows involved in some > parts of the plan? > Hei More information: If we turn off enable_indexscan the runtime gets more similar to the one we get with 9.1, we are down to 4200ms. The query plan with this configuration is here: http://explain.depesz.com/s/jVR The question remains the same, why is 9.2 using such a different and bad plan compared to 9.1, when the data and the configuration are the same? regards, - -- Rafael Martinez Guerrero Center for Information Technology University of Oslo, Norway PGP Public Key: http://folk.uio.no/rafael/ -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (GNU/Linux) iEYEARECAAYFAlIcbx8ACgkQBhuKQurGihReJgCcCiEfGQ0rZHcazlN3Ihb2PeCn jOsAnjkh1M0j4r1DQJ4Xb1djZ+y4mji3 =Td8b -----END PGP SIGNATURE----- -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
