Re: PostgreSQL db, 30 tables with number of rows < 100 (not huge) - the fastest way to clean each non-empty table and reset unique identifier column of empty ones.

On Fri, Jul 6, 2012 at 4:29 AM, Craig Ringer <ringerc@ringerc.id.au> wrote:
> On 07/03/2012 11:22 PM, Stanislaw Pankevich wrote:

> > 1) Truncate each table. It is too slow, I think, especially for empty
> > tables.
>
> Really?!? TRUNCATE should be extremely fast, especially on empty tables.
>
> You're aware that you can TRUNCATE many tables in one run, right?
>
> TRUNCATE TABLE a, b, c, d, e, f, g;

This still calls DropRelFileNodeAllBuffers once for each table (and
each index), even if the table is empty.

With large shared_buffers, this can be relatively slow.

Cheers,

Jeff