Re: Size for vacuum_mem

On 5 Dec 2002, Neil Conway wrote:

> For these, it would probably be faster to TRUNCATE the table and then
> load the new data, then ANALYZE.

I can't because those tables would not be usable during the load.
Right now I do delete/copy from within a transaction. If the loads are
still running while people start coming in the morning they can still do
work.

> >  while other tables I delete/reload about 1/3 (ie
> > 7 Million records table I delete/copy 1.5 Million records).
>
> For these, you can try just using a plain VACUUM and seeing how
> effective that is at reclaiming space.

I am not too concerned with space reclamation. In theory if I don't do
vacuum fulls I may have some dead space, but it would get re-used daily.
My concern is the performance hit I would suffer with the table scans.

>If necessary, increase max_fsm_pages.

What is this setting for? To what number could I increase it to?

> You might also want to check and see if your indexes are growing in size
> (btree indexes on incrementally increasing values like timestamps can
> grow, even with VACUUM FULL); use REINDEX if that's the case.

Every once in a while I truncate the tables and re-load the whole set.
Probably about every couple of months.