Horton

Re: Should we remove vacuum_defer_cleanup_age?

Greg Stark <stark@mit.edu>

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From: Greg Stark <stark@mit.edu>
To: Laurenz Albe <laurenz.albe@cybertec.at>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, "Jonathan S. Katz" <jkatz@postgresql.org>, Robert Haas <robertmhaas@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Andres Freund <andres@anarazel.de>, Justin Pryzby <pryzby@telsasoft.com>, pgsql-hackers@postgresql.org
Date: 2023-04-14T18:08:56Z
Lists: pgsql-hackers

Commits

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

  1. Rework text in replication slots documentation

  2. Remove vacuum_defer_cleanup_age

  3. Allow read only connections during recovery, known as Hot Standby.

On Fri, 14 Apr 2023 at 13:15, Laurenz Albe <laurenz.albe@cybertec.at> wrote:
>
> On Fri, 2023-04-14 at 18:43 +0200, Alvaro Herrera wrote:
> > On 2023-Apr-14, Greg Stark wrote:
> > > I assume people would use hot_standby_feedback if they have streaming
> > > replication.
> >
> > Yes, either that or a replication slot.
>
> A replication slot doesn't do anything against snapshot conflicts,
> which is what we are discussing here.  Or are we not?

They're related -- the replication slot holds the feedback xmin so
that if your standby disconnects it can reconnect later and not have
lost data in the meantime. At least I think that's what I think it
does -- I don't know if I'm just assuming that, but xmin is indeed in
pg_replication_slots.

-- 
greg