-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello We are having some performance problems with an application that uses prepared statement heavily. We have found out that it creates-executes-destroys a prepared statement *per* statement it sends to the database (pg-9.1) via DBD-Pg. A normal log entry for a sql-statement looks e.g. like this: - ---------------------------------------------------------- [2012-03-15 14:49:12.484 CET] LOG: duration: 8.440 ms parse dbdpg_p32048_3: SELECT DISTINCT ACL.RightName FROM ACL, Principals, CachedGroupMembers WHERE Principals.id = ACL.PrincipalId AND Principals.PrincipalType = 'Group' AND Principals.Disabled = 0 AND CachedGroupMembers.GroupId = ACL.PrincipalId AND CachedGroupMembers.GroupId = Principals.id AND CachedGroupMembers.MemberId = 19312 AND CachedGroupMembers.Disabled = 0 AND ((ACL.ObjectType = 'RT::System' AND ACL.ObjectId = 1) OR (ACL.ObjectType = 'RT::System' AND ACL.ObjectId = 1)) [2012-03-15 14:49:12.485 CET] LOG: duration: 0.087 ms bind dbdpg_p32048_3: SELECT DISTINCT ACL.RightName FROM ACL, Principals, CachedGroupMembers WHERE Principals.id = ACL.PrincipalId AND Principals.PrincipalType = 'Group' AND Principals.Disabled = 0 AND CachedGroupMembers.GroupId = ACL.PrincipalId AND CachedGroupMembers.GroupId = Principals.id AND CachedGroupMembers.MemberId = 19312 AND CachedGroupMembers.Disabled = 0 AND ((ACL.ObjectType = 'RT::System' AND ACL.ObjectId = 1) OR (ACL.ObjectType = 'RT::System' AND ACL.ObjectId = 1)) [2012-03-15 14:49:12.487 CET] LOG: duration: 1.692 ms execute dbdpg_p32048_3: SELECT DISTINCT ACL.RightName FROM ACL, Principals, CachedGroupMembers WHERE Principals.id = ACL.PrincipalId AND Principals.PrincipalType = 'Group' AND Principals.Disabled = 0 AND CachedGroupMembers.GroupId = ACL.PrincipalId AND CachedGroupMembers.GroupId = Principals.id AND CachedGroupMembers.MemberId = 19312 AND CachedGroupMembers.Disabled = 0 AND ((ACL.ObjectType = 'RT::System' AND ACL.ObjectId = 1) OR (ACL.ObjectType = 'RT::System' AND ACL.ObjectId = 1)) [2012-03-15 14:49:12.488 CET] LOG: duration: 0.029 ms statement: DEALLOCATE dbdpg_p32048_3 - ---------------------------------------------------------- As you can see, the parse+bind+deallocate part uses much more time than the execution part. This is the same for many of the statements send to the database. My question is: Is the parse+bind time reported, a time (not reported) that the planer will use anyway when running a sql-statement in a normal way or the parse+bind+deallocate time is *extra* time needed by the prepared statement? Can we assume that running this application without using prepared statements will do that it runs faster the time used by parse+bind+deallocate? Thanks in advance. 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 v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk9pubAACgkQBhuKQurGihTYkwCcCFYQRDGWD0yaR+f2FFwKs7gN RfgAoJdPrAzUhfBfsXmst7/l7LVLisHy =l7Fl -----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
