Re: min_safe_lsn column in pg_replication_slots view

Alvaro Herrera <alvherre@2ndquadrant.com>

From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgbf@twiska.com, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, masao.fujii@oss.nttdata.com, pgsql-hackers@lists.postgresql.org
Date: 2020-07-08T23:35:26Z
Lists: pgsql-hackers
On 2020-Jul-08, Tom Lane wrote:
> Alvaro Herrera <alvherre@2ndquadrant.com> writes:

> > Anyway the error is pretty strange: only GetWALAvailability is showing a
> > problem, but the size calculation in the view function def is returning
> > a negative number, as expected.
> 
> We've previously noted what seem to be compiler optimization bugs on
> both sparc32 and sparc64; the latest thread about that is
> https://www.postgresql.org/message-id/flat/f28f842d-e82b-4e30-a81a-2a1f9fa4a8e1%40www.fastmail.com
> 
> This is looking uncomfortably like the same thing.

Ouch.  So 12 builds with -O0 but 13 does not?  Did we do something to
sequence.c to work around this problem?  I cannot find anything.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



Commits

  1. Fix uninitialized value in segno calculation

  2. Morph pg_replication_slots.min_safe_lsn to safe_wal_size