Thread: pgsql: Improve comment about dropped entries in pgstat.c

pgsql: Improve comment about dropped entries in pgstat.c

From
Michael Paquier
Date:
Improve comment about dropped entries in pgstat.c

pgstat_write_statsfile() discards any entries marked as dropped from
being written to the stats file at shutdown, and also included an
assertion based on the same condition.

The intention of the assertion is to track that no pgstats entries
should be left around as terminating backends should drop any entries
they still hold references on before the stats file is written by the
checkpointer, and it not worth taking down the server in this case if
there is a bug making that possible.

Let's improve the comment of this area to document clearly what's
intended.

Based on a discussion with Bertrand Drouvot and Anton A. Melnikov.

Author: Bertrand Drouvot
Discussion: https://postgr.es/m/a13e8cdf-b97a-4ecb-8f42-aaa367974e29@postgrespro.ru
Backpatch-through: 15

Branch
------
REL_15_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/a0ab20f16541cab2a2094433b3b812b1db2392f1

Modified Files
--------------
src/backend/utils/activity/pgstat.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)