On 2021-Jan-13, James Coleman wrote: > On Wed, Jan 13, 2021 at 12:33 PM Alvaro Herrera <alvhe...@alvh.no-ip.org> > wrote:
> > This is true. So I propose > > > > Like any long-running transaction, <command>REINDEX</command> can > > affect which tuples can be removed by concurrent > > <command>VACUUM</command> > > on any table. > > That sounds good to me. Great, pushed with one more wording tweak: "REINDEX on any table can affect ... on any other table". To pg12 and up. I wondered about noting whether only processes in the current database are affected, but then I noticed that the current code since commit dc7420c2c927 uses a completely different algorithm than what we had with GetOldestXmin() and does not consider database boundaries at all. This doesn't sound great to me, since a misbehaved database can now affect others ... Maybe I misunderstand that code. -- Álvaro Herrera 39°49'30"S 73°17'W "This is what I like so much about PostgreSQL. Most of the surprises are of the "oh wow! That's cool" Not the "oh shit!" kind. :)" Scott Marlowe, http://archives.postgresql.org/pgsql-admin/2008-10/msg00152.php
