Ioannis <Ioannis(dot)Kappas(at)dante(dot)org(dot)uk> writes:
> ....and I really do run vacuum when I clean the table.
You should run it more often than that. Any update or delete on the
table will result in space that can't be reused until you run VACUUM.
PG has to scan all that empty space to make sure there are no valid
records in it whenever you do a query.
Run it at least every night.
-Doug
--
Let us cross over the river, and rest under the shade of the trees.
--T. J. Jackson, 1863