On 2019-Apr-25, Michael Paquier wrote:
> 2) Bisecting between the merge base points of REL9_4_STABLE/master and
> REL9_5_STABLE/master, I am being pointed to the introduction of
> replication origins:
> commit: 5aa2350426c4fdb3d04568b65aadac397012bbcb
> author: Andres Freund <andres@anarazel.de>
> date: Wed, 29 Apr 2015 19:30:53 +0200
> Introduce replication progress tracking infrastructure.
>
> In order to see the problem, also one needs to patch initdb.c so as
> the final VACUUM FULL on pg_database is replaced by VACUUM as on
> 9.6~. The root of the problem is actually surprising, but manually
> testing on 5aa2350 commit and 5aa2350~1 the difference shows up as the
> issue is easily reproducible here.
Hmm ... I suspect the problem is even older, and that this commit made
it possible to see as a side effect of changing the catalog contents
(since it creates one more view and does a REVOKE, which becomes an
update on pg_class.)
--
Álvaro Herrera https://www.2ndQuadrant.com/
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