"Shane Wright" <shane(dot)wright(at)edigitalresearch(dot)com> writes:
> Incidentally, how many passes of a table can vacuum make!
Lots, especially if the table hasn't been vacuumed in a long time...
Perhaps you should be using a higher maintenance_work_mem?
(Um, in 7.4 make that vacuum_mem.) Larger work memory translates
directly to fewer passes over the indexes.
regards, tom lane