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Re: CREATE INDEX CONCURRENTLY does not index prepared xact's data

Andrey Borodin <x4mmm@yandex-team.ru>

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From: Andrey Borodin <x4mmm@yandex-team.ru>
To: Noah Misch <noah@leadboat.com>
Cc: Michael Paquier <michael@paquier.xyz>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-bugs@lists.postgresql.org
Date: 2021-07-18T05:17:28Z
Lists: pgsql-bugs 

> 18 июля 2021 г., в 01:12, Noah Misch <noah@leadboat.com> написал(а):
> 
> Suppose some transaction has a vxid but no xid.  Shortly after
> GetLockConflicts(), it acquires an xid, modifies the table, and issues PREPARE
> TRANSACTION.  Could that cause a corrupt index even with this diff?

Firstly I've tried to stress things out. This little go program [0] easily reproduces corruption on patched code.
Meanwhile vxid->xid->2px program does not [1] (both patched and unpatched).

I think CIC does not care much about VXIDs at all. It's only important when real XID started: before GetLockConflicts() or after.

Thanks!


Best regards, Andrey Borodin.

[0] https://gist.github.com/x4m/8b6025995eedf29bf588727375014dfc#file-stress-xid-2px
[1] https://gist.github.com/x4m/8b6025995eedf29bf588727375014dfc#file-stress-vxid-xid-2px

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Improve contrib/amcheck's tests for CREATE INDEX CONCURRENTLY.

  2. Fix minor memory leaks in pg_dump.

  3. Avoid race in RelationBuildDesc() affecting CREATE INDEX CONCURRENTLY.

  4. Fix CREATE INDEX CONCURRENTLY for the newest prepared transactions.

  5. Add -w back to the flags for pg_ctl (re)start in PostgresNode

  6. Fix CREATE INDEX CONCURRENTLY for simultaneous prepared transactions.