On Mon, Aug 8, 2016 at 7:03 PM, Bruce Momjian <br...@momjian.us> wrote: > It seems asking users to run pg_test_timing before deploying to check > the overhead would be sufficient.
I'am not sure. Time measurement for waits is slightly more complicated than a time measurement for explain analyze: a good workload plus using gettimeofday in a straightforward manner can cause huge overhead. Thats why a proper testing is important - if we can see a significant performance drop if we have for example large shared_buffers with the same concurrency, that shows gettimeofday is too expensive to use. Am I correct, that we do not have such accurate tests now? My another concern is, that it is a bad idea to release a feature, which allegedly has huge performance impact even if it is not turned on by default. I often meet people who do not use exceptions in plpgsql because a tip "A block containing an EXCEPTION clause is significantly more expensive to enter ..." in PostgreSQL documentation -- Ilya Kosmodemiansky, PostgreSQL-Consulting.com tel. +14084142500 cell. +4915144336040 i...@postgresql-consulting.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers