Christopher Kings-Lynne wrote:
>> The point here is that if tuples require 50 bytes, and there are 20
>> bytes free on a page, pgstattuple counts 20 free bytes while FSM
>> ignores the page. Recording that space in the FSM will not improve
>> matters, it'll just risk pushing out FSM records for pages that do
>> have useful amounts of free space.
>
>
>
> Maybe an overloaded pgstattuple function that allows you to request FSM
> behavior?
>
That's a nice idea - could also do equivalently by adding an extra
column "usable_free_space" or some such, and calculating this using FSM
logic.
Cheers
Mark