Re: Excessive growth of pg_attribute and other system tables

Steve Crawford <scrawford(at)pinpointresearch(dot)com> writes:
> On Thursday 17 March 2005 3:51 pm, Tom Lane wrote:
>> Do you have the FSM settings set large enough to account for all
>> the free space?

> max_fsm_pages = 20000
> max_fsm_relations = 1000

That doesn't sound like nearly enough pages for a 2G database.
20000 * 8K = 160MB, so if more than 10% of the pages in your DB
are dirty you are going to be leaking free space. You probably
want max_fsm_pages up around 250,000.

> I just poked through the cluster. I have 6 user databases plus
> template0 and template1. Total tables in the cluster has reached
> slightly over 1,000 user tables plus all the system tables in the 8
> databases. Does this indicate that I need to increase
> max_fsm_relations to greater than the total number of tables in the
> cluster?

That would be a good plan too.

> pg_autovacuum is from 7.4.6 release and is showing periodic vacuums of
> the problem tables. I thought that bug was in some release prior to
> 7.4.6. Does the bug allow it to show a vacuum taking place but not do
> it?

I don't recall the details of the changes; you could look at the CVS
logs to see what got fixed when. But in any case I think we see the
main problem: max_fsm_pages too small.

regards, tom lane