Hi, On Tue, 17 Sept 2024 at 16:07, Bertrand Drouvot <bertranddrouvot...@gmail.com> wrote: > On Tue, Sep 17, 2024 at 02:52:01PM +0300, Nazir Bilal Yavuz wrote: > > Could we remove pg_stat_get_my_io() completely and use > > pg_stat_get_backend_io() with the current backend's pid to get the > > current backend's stats? > > The reason why I keep pg_stat_get_my_io() is because (as mentioned in [1]), > the > statistics snapshot is build for "my backend stats" (means it depends of the > stats_fetch_consistency value). I can see use cases for that. > > OTOH, pg_stat_get_backend_io() behaves as if stats_fetch_consistency is set to > none (each execution re-fetches counters from shared memory) (see [2]). > Indeed, > the snapshot is not build in each backend to copy all the others backends > stats, > as 1/ I think that there is no use case (there is no need to get others > backends > I/O statistics while taking care of the stats_fetch_consistency) and 2/ that > could be memory expensive depending of the number of max connections. > > So I think it's better to keep both functions as they behave differently. > > Thoughts?
Yes, that is correct. Sorry, you already had explained it and I had agreed with it but I forgot. > > If you meant the same thing, please don't > > mind it. > > What I meant to say is to try to remove the duplicate code that we can find in > those 3 functions (say creating a new function that would contain the > duplicate > code and make use of this new function in the 3 others). Did not look at it in > details yet. I got it, thanks for the explanation. -- Regards, Nazir Bilal Yavuz Microsoft
