Re: [Proposal] Global temporary tables - Mailing list pgsql-hackers

From Wenjing Zeng
Subject Re: [Proposal] Global temporary tables
Date
Msg-id 3A8BA4EF-A42B-492D-9F03-2F086F902838@gmail.com
Whole thread Raw
In response to Re: [Proposal] Global temporary tables  (Andres Freund <andres@anarazel.de>)
Responses Re: [Proposal] Global temporary tables  (Adam Brusselback <adambrusselback@gmail.com>)
List pgsql-hackers

> 2022年2月27日 12:13,Andres Freund <andres@anarazel.de> 写道:
>
> Hi,
>
> On 2022-02-27 04:17:52 +0100, Pavel Stehule wrote:
>>> You redirect stats from pg_class and pg_statistics to a local hash table.
>>> This is pretty hairy :(
>
> As is I think the patch is architecturally completely unacceptable. Having
> code everywhere to redirect to manually written in-memory catalog table code
> isn't maintainable.
>
>
>>> I guess you'd also need to handle pg_statistic_ext and ext_data.
>>> pg_stats doesn't work, since the data isn't in pg_statistic - it'd need to
>>> look
>>> at pg_get_gtt_statistics.
>>
>> Without this, the GTT will be terribly slow like current temporary tables
>> with a lot of problems with bloating of pg_class, pg_attribute and
>> pg_depend tables.
>
> I think it's not a great idea to solve multiple complicated problems at
> once...

I'm trying to break down the entire implementation into multiple sub-patches.


Regards, Wenjing.


>
> Greetings,
>
> Andres Freund
>
>




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