Horton

Re: [Proposal] Global temporary tables

Prabhat Sahu <prabhat.sahu@enterprisedb.com>

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From: Prabhat Sahu <prabhat.sahu@enterprisedb.com>
To: 曾文旌 <wenjing.zwj@alibaba-inc.com>
Cc: Pavel Stehule <pavel.stehule@gmail.com>, tushar <tushar.ahuja@enterprisedb.com>, Robert Haas <robertmhaas@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Konstantin Knizhnik <k.knizhnik@postgrespro.ru>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, 蔡松露(子嘉) <zijia@taobao.com>, "Cai, Le" <le.cai@alibaba-inc.com>
Date: 2020-04-27T13:48:04Z
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.

Thanks Wenjing, for the fix patch for previous issues.
I have verified the issues, now those fix look good to me.
But the below error message is confusing(for gtt2).

postgres=# drop table gtt1;
ERROR:  cannot drop global temp table gtt1 when other backend attached it.

postgres=# drop table gtt2;
ERROR:  cannot drop index idx2 on global temp table gtt2 when other backend
attached it.

I feel the above error message shown for "DROP TABLE gtt2;" is a bit
confusing(looks similar to DROP INDEX gtt2;).
If possible, can we keep the error message simple as "ERROR:  cannot drop
global temp table gtt2 when other backend attached it."?
I mean, without giving extra information for the index attached to that GTT.

On Mon, Apr 27, 2020 at 5:34 PM 曾文旌 <wenjing.zwj@alibaba-inc.com> wrote:

>
>
> 2020年4月27日 下午5:26，Prabhat Sahu <prabhat.sahu@enterprisedb.com> 写道：
>
> Hi Wenjing,
>
> Please check the below scenario shows different error message with "DROP
> TABLE gtt;" for gtt with and without index.
>
> *-- Session1:*postgres=# create global temporary table gtt1 (c1 int);
> CREATE TABLE
> postgres=# create global temporary table gtt2 (c1 int);
> CREATE TABLE
> postgres=# create index idx2 on gtt2(c1);
> CREATE INDEX
>
>
> *-- Session2:*postgres=# drop table gtt1;
> ERROR:  can not drop relation gtt1 when other backend attached this global
> temp table
> postgres=# drop table gtt2;
> ERROR:  can not drop index gtt2 when other backend attached this global
> temp table.
>
> For DROP GTT, we need to drop the index on the table first.
> So the indexes on the GTT are checked first.
> But the error message needs to be fixed.
> Fixed in v32
>
>
> wenjing
>
>
>
>
>
> --
>
> With Regards,
> Prabhat Kumar Sahu
> EnterpriseDB: http://www.enterprisedb.com
>
>
>

-- 

With Regards,
Prabhat Kumar Sahu
EnterpriseDB: http://www.enterprisedb.com