On 4/2/19 7:06 PM, Magnus Hagander wrote:
On Tue, Apr 2, 2019 at 8:47 AM Michael Paquier <mich...@paquier.xyz <mailto:mich...@paquier.xyz>> wrote: On Tue, Apr 02, 2019 at 07:43:12AM +0200, Julien Rouhaud wrote: > On Tue, Apr 2, 2019 at 6:56 AM Michael Paquier <mich...@paquier.xyz <mailto:mich...@paquier.xyz>> wrote: >> One thing which is not >> proposed on this patch, and I am fine with it as a first draft, is >> that we don't have any information about the broken block number and >> the file involved. My gut tells me that we'd want a separate view, >> like pg_stat_checksums_details with one tuple per (dboid, rel, fork, >> blck) to be complete. But that's just for future work. > > That could indeed be nice. Actually, backpedaling on this one... pg_stat_checksums_details may be a bad idea as we could finish with one row per broken block. If a corruption is spreading quickly, pgstat would not be able to sustain that amount of objects. Having pg_stat_checksums would allow us to plugin more data easily based on the last failure state: - last relid of failure - last fork type of failure - last block number of failure. Not saying to do that now, but having that in pg_stat_database does not seem very natural to me. And on top of that we would have an extra row full of NULLs for shared objects in pg_stat_database if we adopt the unique view approach... I find that rather ugly. I think that tracking each and every block is of course a non-starter, as you've noticed.
I think that's less of a concern now that the stats collector process has gone and that the stats are now collected in shared memory, what do you think? Regards, -- Bertrand Drouvot PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com
