About two weeks ago we had a discussion that concluded that notice
messages put out by GUC assign hooks should be logged when there's
a problem with a postgresql.conf setting, leading to this patch:
http://archives.postgresql.org/pgsql-committers/2007-12/msg00298.php
I noticed today that running pg_dump now causes a message like this
in the postmaster log:
LOG: SET TRANSACTION ISOLATION LEVEL must be called before any query
and investigation shows it's because of that patch. pg_dump allows
its serializable transaction to be rolled back at exit, and the
assign hook for XactIsoLevel has
if (SerializableSnapshot != NULL) { ereport(GUC_complaint_elevel(source),
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION), errmsg("SET TRANSACTION ISOLATION LEVEL must be called before
anyquery"))); /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */ if (source !=
PGC_S_OVERRIDE) return NULL; }
and as you can probably tell from the comment, AtEOXact_GUC passes
source == PGC_S_OVERRIDE when it's trying to roll back a
within-transaction setting. So we'd better do something about that,
or we're going to see a lot of complaints about unexpected log messages.
One possibility is to change the logic to
if (SerializableSnapshot != NULL) { /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
if (source != PGC_S_OVERRIDE) { ereport(GUC_complaint_elevel(source),
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION), errmsg("SET TRANSACTION ISOLATION LEVEL must be called
beforeany query"))); return NULL; } }
but this seems a bit ugly, mainly because quite a few places would have
to be touched. I'm considering leaving the assign hooks as-is and
making GUC_complaint_elevel() return DEBUG5 for source ==
PGC_S_OVERRIDE, which would hide the chatter for all but the most
verbose logging.
Thoughts?
regards, tom lane
