Manfred Koizar <mkoi-pg@aon.at> writes:
> Here I'm lost. The effect you mention explains growth up to a state
> where each toast table page holds 3 instead of 4 tuples (1.33 *
> initial size). Now with each UPDATE we get pages with significantly
> more free space than 2K.
Good point, it should still stabilize with at worst 33% overhead. So
maybe I'm barking up the wrong tree.
Still, the FSM code is new in 7.2 and I'm quite prepared to believe that
the effect Mark is seeing indicates some problem in it. Anyone care to
sit down and read through freespace.c? It's pretty liberally commented.
regards, tom lane