Hi, Thank you for looking into this!
On Sun, 9 Jun 2024 at 18:05, Nitin Jadhav <nitinjadhavpostg...@gmail.com> wrote: > > > If possible, let's have all the I/O stats (even for WAL) in > > pg_stat_io. Can't we show the WAL data we get from buffers in the hits > > column and then have read_bytes or something like that to know the > > amount of data read? > > The ‘hits’ column in ‘pg_stat_io’ is a vital indicator for adjusting a > database. It signifies the count of cache hits, or in other words, the > instances where data was located in the ‘shared_buffers’. As a result, > keeping an eye on the ‘hits’ column in ‘pg_stat_io’ can offer useful > knowledge about the buffer cache’s efficiency and assist users in > making educated choices when fine-tuning their database. However, if > we include the hit count of WAL buffers in this, it may lead to > misleading interpretations for database tuning. If there’s something > I’ve overlooked that’s already been discussed, please feel free to > correct me. I think counting them as a hit makes sense. We read data from WAL buffers instead of reading them from disk. And, WAL buffers are stored in shared memory so I believe they can be counted as hits in the shared buffers. Could you please explain how this change can 'lead to misleading interpretations for database tuning' a bit more? -- Regards, Nazir Bilal Yavuz Microsoft
