On Tue, Apr 5, 2022 at 8:00 PM Andres Freund <andres@anarazel.de> wrote:
Here comes v70:
One thing I just noticed while peeking at pg_stat_slru:
The stats_reset column for my newly initdb'd cluster is showing me "2000-01-01 00:00:00" (v15). I was expecting null, though a non-null value restriction does make sense. Neither choice is documented though.
Based upon my expectation I checked to see if v14 reported null, and thus this was a behavior change. v14 reports the initdb timestamp (e.g., 2022-04-13 23:26:48.349115+00)
Can we document the non-null aspect of this value (pg_stat_database is happy being null, this seems to be a "fixed" type behavior) but have it continue to report initdb as its initial value?
Sorry, apparently this "2000-01-01" behavior only manifests after crash recovery on v15 (didn't check v14); after a clean initdb on v15 I got the same initdb timestamp.
Feels like we should still report the "end of crash recovery timestamp" for these instead of 2000-01-01 (which I guess is derived from 0) if we are not willing to produce null (and it seems other parts of the system using these stats assumes non-null).
