On Wed, Jun 18, 2008 at 12:29:46PM -0700, Mark Wilden wrote: > My coworker and I are having an argument about whether it's necessary > to VACUUM an insert-only table. > > My theory is that since there are no outdated nor deleted rows, VACUUM > doesn't do anything. Rolled back transactions on an insert-only table can leave behind dead rows. Also, even if the table never has dead rows you still have to vacuum periodically to prevent transaction ID wraparound. http://www.postgresql.org/docs/8.3/interactive/routine-vacuuming.html#VACUUM-FOR-WRAPAROUND "To avoid this, it is necessary to vacuum every table in every database at least once every two billion transactions." -- Michael Fuhr
