Horton

Re: [Proposal] Global temporary tables

Konstantin Knizhnik <k.knizhnik@postgrespro.ru>

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From: Konstantin Knizhnik <k.knizhnik@postgrespro.ru>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, 曾文旌(义从) <wenjing.zwj@alibaba-inc.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: 2020-01-29T17:21:20Z
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.


On 29.01.2020 20:08, Pavel Stehule wrote:
>
>
>
>     2. Actually I do not propose some completely new approach. I try to
>     provide behavior with is compatible with regular tables.
>     If you create index for regular table, then it can be used in all
>     sessions, right?
>
>
> I don't understand to this point. Regular tables shares data, shares 
> files. You cannot to separate it. More - you have to uses relatively 
> aggressive locks to be this operation safe.
>
> Nothing from these points are valid for GTT.

GTT shares metadata.
As far as them are not sharing data, then GTT are safer than regular 
table, aren't them?
"Safer" means that we need less "aggressive" locks for them: we need to 
protect only metadata, not data itself.

My point is that if we allow other sessions to access created indexes 
for regular tables, then it will be not more complex to support it for GTT.
Actually "not more complex" in this case means "no extra efforts are 
needed".

-- 
Konstantin Knizhnik
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company