Re: ALTER TABLE on system catalogs

On 08/02/2019 04:04, Kyotaro HORIGUCHI wrote:
> By the way, I'm confused to see that attributes that don't want
> to go external are marked as 'x' in system catalogs. Currently
> (putting aside its necessity) the following operation ends with
> successful attaching a new TOAST relation, which we really don't
> want.
>
> ALTER TABLE pg_attribute ALTER COLUMN attrelid SET STORAGE plain;
>
> Might be silly, but couldn't we have another storage class? Say,
> Compression, which means try compress but don't go external.

That already exists: 'm': Value can be stored compressed inline

I agree that it seems we should be using that for those tables that
don't have a toast table. Maybe the genbki stuff could do it
automatically for the appropriate catalogs.

--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services