Re: Maximum reasonable free space map

On Wed, Dec 17, 2008 at 5:45 AM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> wrote:
> It's all about the size of your tables. If you've got 1 table with
> 100k rows that's updated a lot then an fsm of 100k is likely
> reasonable, assuming you've got autovac keeping things in check. Got
> 4G rows but none are ever updated, then you don't need much if any
> fsm.
>
> If you've got 40M rows and 10% are updated each day, then it's likely
> you'll want 4M fsm entries avaialble for those dead rows.
>
> I think that as long as you're not using a huge amount of shared
> memory it's nothing to worry about much, as long as it's not too
> small. We had to go to 1Million fsm entries because we routinely have
> 400k to 600k dead rows in our db at work.

That's why I said - go for whatever vacuum suggests you on production,
with assumption that db is vacuum regularly.

--
GJ