Hi, I have a DB with a large number schemas (around 10K) and a large number of tables (400K). The app became slow lately, and logging the slow queries, I see more than a few like this: SELECT: LOG: duration: 169547.424 ms statement: SELECT attr.attname, name.nspname, seq.relname FROM pg_class seq, pg_attribute attr, pg_depend dep, pg_namespace name, pg_constraint cons WHERE seq.oid = dep.objid AND seq.relnamespace = name.oid AND seq.relkind = 'S' AND attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid AND attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1] AND cons.contype = 'p' AND dep.refobjid = 'activities'::regclass Almost all slow queries are of this type, though most of those do finish really fast. From time to time it gets really slow. Some details on the setup: Dual Opteron with 4GB RAM RAID1 for WAL on 10K SCSI RAID10 over 6 x 10K scsi drives for main the rest for the DB files Auto vaccum is on, and in addition I do some vacuuming for specific high use tables nightly Any ideas how to start finding the culprit? Bye, Guy. -- Family management on rails: http://www.famundo.com My development related blog: http://devblog.famundo.com -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general