Horton

Re: [Proposal] Global temporary tables

Pavel Stehule <pavel.stehule@gmail.com>

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From: Pavel Stehule <pavel.stehule@gmail.com>
To: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>, 曾文旌(义从) <wenjing.zwj@alibaba-inc.com>, Konstantin Knizhnik <k.knizhnik@postgrespro.ru>, Robert Haas <robertmhaas@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, 蔡松露(子嘉) <zijia@taobao.com>, "Cai, Le" <le.cai@alibaba-inc.com>, 萧少聪(铁庵) <shaocong.xsc@alibaba-inc.com>
Date: 2020-01-06T13:50:49Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. PageAddItemExtended(): Add LP_UNUSED assertion.

  2. Remove temporary files after backend crash

  3. Fix comment in indexing.c

  4. Fix failure to ignore leftover temp tables after a server crash.

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

> On Mon, 6 Jan 2020 at 11:01, Tomas Vondra <tomas.vondra@2ndquadrant.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
>