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_4_STABLE
Details
-------
http://git.postgresql.org/pg/commitdiff/edd8873ffede137e7af9cba5073ebb218e29704b
Modified Files
--------------
src/backend/commands/vacuum.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
