Re: vacuum pg_attribute causes high load

kris pal wrote:

>
> Christopher,
>
> Thanks for your detailed response. Now I get the idea why vacuum is
> causing so much load. We should have vacuumed the database more often
> but didn't do it as we are more used to managing Oracle databases. This
> is the first Postgres instance that I am managing.
>
> The datafile for production database ("bbs") is abt 6GB, though the
> actual data is very small, abt 20MB. I used the dump (from pg_dump of
> "bbs") of the production database  to import into a "test_database" -
> its datafile size was < 20MB.
>
> So instead of going through all these, am planning to have down time of
> 15 mins and do the following:
>
> 1)"pg_dump bmgs"
> 2)"drop the database  bmgs"
> ** (this should essentially free up all the space occupied by
> pg_attribute and its indexes - right ?? )
> 3)"recreate database bmgs"
> and
> 4)import the dump from step 1) into bmgs created in  step 3)
>
>
> Do you think there will be issues with this approach? The system catalog
> will be built from scratch, and there won't be any data loss right. That
> way I can reclaim the space and then run Vacuum more often.

Before to do it be sure that your pg_dump is non affected by not well ordered
objects, if yes you have to reorder the order creation ( manually ) in the dump,
some times happen.


Regards
Gaetano Mendola