From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | pgsql-committers(at)lists(dot)postgresql(dot)org |
Subject: | pgsql: Avoid spamming the client with multiple ParameterStatus messages |
Date: | 2020-11-25 16:40:54 |
Message-ID: | E1khxqg-0003XW-Pf@gemulon.postgresql.org |
Views: | Whole Thread | Raw Message | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-committers |
Avoid spamming the client with multiple ParameterStatus messages.
Up to now, we sent a ParameterStatus message to the client immediately
upon any change in the active value of any GUC_REPORT variable. This
was only barely okay when the feature was designed; now that we have
things like function SET clauses, there are very plausible use-cases
where a GUC_REPORT variable might change many times within a query
--- and even end up back at its original value, perhaps. Fortunately
most of our GUC_REPORT variables are unlikely to be changed often;
but there are proposals in play to enlarge that set, or even make it
user-configurable.
Hence, let's fix things to not generate more than one ParameterStatus
message per variable per query, and to not send any message at all
unless the end-of-query value is different from what we last reported.
Discussion: https://postgr.es/m/5708.1601145259@sss.pgh.pa.us
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/2432b1a04087edc2fd9536c7c9aa4ca03fd1b363
Modified Files
--------------
src/backend/tcop/postgres.c | 3 ++
src/backend/utils/misc/guc.c | 78 ++++++++++++++++++++++++++++++++++++++----
src/include/utils/guc.h | 1 +
src/include/utils/guc_tables.h | 5 ++-
4 files changed, 80 insertions(+), 7 deletions(-)
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2020-11-25 19:04:40 | pgsql: Doc: minor improvements for section 11.2 "Index Types". |
Previous Message | Peter Eisentraut | 2020-11-25 14:31:03 | pgsql: tablefunc: Reject negative number of tuples passed to normal_ran |