Message-ID: <3aad711d-1eea-4989-b9e7-261eeffa5f5b@uni-muenster.de>
Date: Thu, 7 May 2026 10:43:01 +0200
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Subject: Re: Fix bug with accessing to temporary tables of other sessions
To: Alexander Korotkov <aekorotkov@gmail.com>,
 Daniil Davydov <3danissimo@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>,
 Soumya S Murali <soumyamurali.work@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>,
 Stepan Neretin <slpmcf@gmail.com>,
 PostgreSQL Hackers <pgsql-hackers@postgresql.org>,
 Mohamed Ali <moali.pg@gmail.com>, Nazneen Jafri <jafrinazneen@gmail.com>,
 Shawn McCoy <shawn.the.mccoy@gmail.com>
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From: Jim Jones <jim.jones@uni-muenster.de>
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On 07/05/2026 10:04, Alexander Korotkov wrote:
> Thus, I don't see the reason why this shouldn't be committed and
> backpatched to PG17 (first release containing b7b0f3f27241).

Quick question: should we work on a separate patch for PG14-PG16? In 
these versions, the error message is raised depending on the temporary 
table's tuple count, as demonstrated in [1]:

== session 1 ==

psql (14.20 (Debian 14.20-1.pgdg13+1))
Type "help" for help.

postgres=# CREATE TEMPORARY TABLE t (id int);
CREATE TABLE
postgres=# \d pg_temp*.*
                 Table "pg_temp_3.t"
  Column |  Type   | Collation | Nullable | Default
--------+---------+-----------+----------+---------
  id     | integer |           |          |

== session 2 ==

psql (14.20 (Debian 14.20-1.pgdg13+1))
Type "help" for help.

postgres=# SELECT * FROM pg_temp_3.t;
  id
----
(0 rows)

== session 1 ==

postgres=# INSERT INTO t VALUES (42);
INSERT 0 1

== session 2 ==

postgres=# SELECT * FROM pg_temp_3.t;
ERROR:  cannot access temporary tables of other sessions

Thanks!

Best, Jim

1 - 
https://www.postgresql.org/message-id/800c75af-9bd0-48ac-b4bf-54cadf2bc723%40uni-muenster.de