Re: "Consider compacting this relation..." ???

On Thu, Feb 28, 2008 at 3:14 PM, Kynn Jones <kynnjo(at)gmail(dot)com> wrote:
> I just ran VACUUM ANALYZE and got this warning I've never seen before:
>
> WARNING: relation "public.some_big_table" contains more than
> "max_fsm_pages" pages with useful free space
> HINT: Consider compacting this relation or increasing the configuration
> parameter "max_fsm_pages".
>
>
> What does the hint mean by "compacting"? What exactly must I do to compact
> this table?

Vacuum full

> Also, at the end of the VACUUM ANALYZE run I get the NOTICE:
>
> NOTICE: number of page slots needed (294528) exceeds max_fsm_pages (153600)
> HINT: Consider increasing the configuration parameter "max_fsm_pages" to a
> value over 294528.
>
>
> What surprises me here is that even though I've never seen this notice
> before (and I've been running VACUUM ANALYZE a lot lately!), the number of
> page slots needed is almost twice as much as the value of max_fsm_pages.
> What could I have done since the last time I ran VACUUM ANALYZE (not more
> than 24 hours ago) to make this "page slot" requirement to shoot through the
> roof like this?

Lots of deletes or updates on the table.