pgsql: Fetch XIDs atomically during vac_truncate_clog(). - Mailing list pgsql-committers

From Tom Lane
Subject pgsql: Fetch XIDs atomically during vac_truncate_clog().
Date
Msg-id E1b5IJO-0002PC-E5@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Fetch XIDs atomically during vac_truncate_clog().

Because vac_update_datfrozenxid() updates datfrozenxid and datminmxid
in-place, it's unsafe to assume that successive reads of those values will
give consistent results.  Fetch each one just once to ensure sane behavior
in the minimum calculation.  Noted while reviewing Alexander Korotkov's
patch in the same area.

Discussion: <8564.1464116473@sss.pgh.pa.us>

Branch
------
REL9_5_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/bbbe2c97eba37fd8a9e580a596f48935f3d9ded8

Modified Files
--------------
src/backend/commands/vacuum.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)


pgsql-committers by date:

Previous
From: Tom Lane
Date:
Subject: pgsql: Fetch XIDs atomically during vac_truncate_clog().
Next
From: Tom Lane
Date:
Subject: pgsql: Fetch XIDs atomically during vac_truncate_clog().