Re: [Proposal] Global temporary tables

po 6. 1. 2020 v 13:17 odesílatel Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
napsal:

> On Mon, 6 Jan 2020 at 11:01, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>
> wrote:
> >
> > On Mon, Jan 06, 2020 at 01:04:15PM +0800, 曾文旌(义从) wrote:
> >
> > >2 We feel that gtt needs to maintain statistics, but there is no
> > >agreement on what it will be done.
> > >
> >
> > I certainly agree GTT needs to maintain statistics, otherwise it'll lead
> > to poor query plans.
>
> +1
>
> > AFAIK the current patch stores the info in a hash
> > table in a backend private memory, and I don't see how else to do that
> > (e.g. storing it in a catalog would cause catalog bloat).
> >
>
> It sounds like it needs a pair of system GTTs to hold the table and
> column statistics for other GTTs. One would probably have the same
> columns as pg_statistic, and the other just the relevant columns from
> pg_class. I can see it being useful for the user to be able to see
> these stats, so perhaps they could be UNIONed into the existing stats
> view.
>

+1

Pavel

> Regards,
> Dean
>