Fernando Mertins wrote: > I have a PostgreSQL 8.3.6 You should consider upgrading to the latest minor release: http://www.postgresql.org/support/versioning http://www.postgresql.org/docs/8.3/static/release.html > My question is, this same query executes many times a day and many > times fast/normal, but why in some cases its run slowly? Especialy > because the "CODCURSO" column is PK and this table has only 3 > registers (tiny table). Two common causes for this are blocking and overloading the I/O system at checkpoint. You might want to turn on logging of checkpoints to see if this happens only during checkpoints. See this page for techniques to look at blocking: http://wiki.postgresql.org/wiki/Lock_Monitoring If neither of these helps, please review this page and post again with more details: http://wiki.postgresql.org/wiki/Guide_to_reporting_problems -Kevin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
