Обсуждение: Reseting statistics counters
If we reset the statistics counters using pg_stat_reset() will it affect the performance of the database? Eg are these the same statistics used by the planner?
Thanks
Hello
2013/10/1 Xenofon Papadopoulos <xpapad@gmail.com>
If we reset the statistics counters using pg_stat_reset() will it affect the performance of the database? Eg are these the same statistics used by the planner?Thanks
these statistics are used only for autovacuum, what I know. So you can impact a autovacuum, but no planner
Regards
Pavel
Pavel
Sorry for the late reply, but as far as I know when you run pg_stat_reset() you should always run analyze manually of the database to populate the statistics.
Strahinja Kustudić | Lead System Engineer | Nordeus
On Tue, Oct 1, 2013 at 1:50 PM, Xenofon Papadopoulos <xpapad@gmail.com> wrote:
If we reset the statistics counters using pg_stat_reset() will it affect the performance of the database? Eg are these the same statistics used by the planner?Thanks
On 16.11.2013 20:49, Strahinja Kustudić wrote: > Sorry for the late reply, but as far as I know when you run > pg_stat_reset() you should always run analyze manually of the > database to populate the statistics. Why? There are two kinds of stats in the database - stats used by the planner (common column values, histograms, ...) and runtime stats. pg_stat_reset only deals with the latter, it won't discard histograms or anything like that. And runnning analyze won't magically populate the runtime stats - for example how could it populate number of sequential/index scans or the timestamp of the last autovacuum? The only thing that may be influenced by this is autovacuum, because this will remove timestamp of the last run on the tables, number of deleted/dead tuples etc. So it will be invoked on all tables, collecting this info. regards Tomas