On Thu, Jul 21, 2022 at 02:37:35PM -0400, bruno da silva wrote: > I'm investigating an issue on a PostgresSql 9.5.21 installation that > becomes unusable in an intermittent way. Simple queries like "select > now();" could take 20s. commits take 2s. and all gets fixed after an engine > restart. > > I look into the pg logs and no signs of errors. and checkpoints are > always timed. The machine is well provisioned, load isn't too high, and cpu > io wait is under 1%. > > any suggestions on what I should check more? What OS/version is it ? What GUCs have you changed ? Is it a new issue ? https://wiki.postgresql.org/wiki/Slow_Query_Questions Operating system+version What OS / version ? At least for linux, you can get the distribution by running: tail /etc/*release GUC Settings What database configuration settings have you changed? What are their values? (These are things like "shared_buffers", "work_mem", "enable_seq_scan", "effective_io_concurrency", "effective_cache_size", etc). See Server Configuration for a useful query that will show all of your non-default database settings, in an easier to read format than posting pieces of your postgresql.conf file. -- Justin