On Thu, Aug 12, 2021 at 09:08:27AM -0400, Alvaro Herrera wrote: > On 2021-Aug-11, hubert depesz lubaczewski wrote: > > > On Wed, Aug 11, 2021 at 10:16:13AM -0400, Alvaro Herrera wrote: > > > 1. this depends on reading the stats file; that's done once per > > > transaction. So if you run the query twice in a transaction, the second > > > time will take less time. You can know how much time is spent reading > > > that file by subtracting both times. > > > > Yeah. I noticed. Looks like loading the stats file is the culprit. But > > does that mean that the whole stats file has to be read at once? I just > > need stats on db, not on relations? > > As I recall there is one file per database containing everything > pertaining to that database, and you cannot read it partially. > > Maybe you can use stats_temp_directory to put these files in faster > or less busy storage -- a RAM disk perhaps? The fie is 120MB, and is stored in tmpfs, which I assume, on Linux, is ram disk. depesz
