+The estimated rowcount on the table "
+Instead of issuing a manual VACUUM ANALYZE command on this table (you can use +the pgAdminIII maintenance menu for this), running VACUUM ANALYZE on a regular +or automated basis should be considered. This can be achieved using a scheduler. PostgreSQL also supplies +the pg_autovacuum daemon, which will track changes made to the database and issue +vacuum commands as required automatically. In most cases, pg_autovacuum will be the +best choice. +
+The PostgreSQL query planner makes its decision based on assumptions, taken from +the estimated rowcount. If the actual rowcount is too different from the estimated rowcount, +the planner might take a wrong decision, resulting in a query plan that is not optimal. This might +result in poor performance. +
+The PostgreSQL storage needs VACUUM to have transaction IDs in tables fixed. +Additionally, outdated rows from updates and deletes are not cleaned up until the VACUUM +command has been issued on that table. In-depth information can be found in the online +documentation, just press the help button. +
+ +