Re: max_fsm_pages

I've read this message, and tryed to apply this changes to my own
database.

sapiens=# vacuum verbose;
...
INFO: free space map: 1 relations, 39 pages stored; 48 total pages
needed
DETAIL: Allocated FSM size: 1000 relations + 30000 pages = 237 kB
shared memory.

1 relation and 48 pages seems too little, considering the defaults in
the configuration.

The database is not too big, just 198 mb (contrib/dbsize tells me so),
and I have 161 relations on pg_class (not counting the catalog).

I'm doing something wrong or 1 relation/48 pages would be just fine?

Thanks.

On Fri, 2003-12-05 at 13:17, Tom Lane wrote:

> Ryan Mahoney <ryan(at)paymentalliance(dot)net> writes:
> > When interactively calculating the ideal value for max_fsm_pages by
> > summarizing the output of VACUUM VERBOSE, which statistic from vacuum am
> > I concerned with?
>
> 7.4 will tell you exactly how many FSM slots you need:
>
> foo=# vacuum verbose;
> ...
> INFO: free space map: 246 relations, 464 pages stored; 4160 total pages needed
> DETAIL: Allocated FSM size: 1000 relations + 20000 pages = 178 kB shared memory.
> VACUUM
>
> In this example, the minimum FSM settings to not discard any data would
> be max_fsm_relations = 246, max_fsm_pages = 4160. Note that you need to
> have vacuumed all databases fairly recently for the totals to be really
> trustworthy.
>
> In previous versions you're kind of on your own :-(
>
> regards, tom lane
>
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