Horton

Re: [Proposal] Global temporary tables

Pavel Stehule <pavel.stehule@gmail.com>

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From: Pavel Stehule <pavel.stehule@gmail.com>
To: Adam Brusselback <adambrusselback@gmail.com>
Cc: Wenjing Zeng <wjzeng2012@gmail.com>, Andres Freund <andres@anarazel.de>, Justin Pryzby <pryzby@telsasoft.com>, wenjing <wenjing@gmail.com>, Andrew Bille <andrewbille@gmail.com>, Tony Zhu <Tony.zhu@ww-it.cn>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-03-02T18:08:12Z
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.

st 2. 3. 2022 v 19:02 odesílatel Adam Brusselback <adambrusselback@gmail.com>
napsal:

> >In my observation, very few users require an accurate query plan for
> temporary tables to
> perform manual analyze.
>
> Absolutely not true in my observations or personal experience. It's one of
> the main reasons I have needed to use (local) temporary tables rather than
> just materializing a CTE when decomposing queries that are too complex for
> Postgres to handle.
>
> I wish I could use GTT to avoid the catalog bloat in those instances, but
> that will only be possible if the query plans are accurate.
>

This strongly depends on usage.  Very common patterns from MSSQL don't need
statistics. But on second thought, sometimes, the query should be divided
and temp tables are used for storing some middle results. In this case, you
cannot exist without statistics. In the first case, the temp tables can be
replaced by arrays. In the second case, the temp tables are not replaceable.

Regards

Pavel