Horton

Re: Parallel vacuum workers prevent the oldest xmin from advancing

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2021-10-19T15:35:56Z
Lists: pgsql-hackers 
Hmm, I think this should happen before the transaction snapshot is
established in the worker; perhaps immediately after calling
StartParallelWorkerTransaction(), or anyway not after
SetTransactionSnapshot.  In fact, since SetTransactionSnapshot receives
a 'sourceproc' argument, why not do it exactly there? ISTM that
ProcArrayInstallRestoredXmin() is where this should happen.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/

Commits

  1. Fix parallel operations that prevent oldest xmin from advancing.