> On Feb 15, 2021, at 3:55 PM, Tom Lane <t...@sss.pgh.pa.us> wrote:
>
> Philip Semanchuk <phi...@americanefficient.com> writes:
>> I saw some unexpected behavior that I'm trying to understand. I suspect it
>> might be a quirk specific to AWS Aurora and I'd like to confirm that.
>
>> When I restart my local Postgres instance (on my Mac), the values in
>> pg_stat_user_tables.n_mod_since_analyze are preserved. In other words, if
>> table foo had n_mod_since_analyze=33 before the reboot, it still has
>> n_mod_since_analyze=33 after the restart.
>
>> When I restart an AWS Aurora instance, the values in
>> pg_stat_user_tables.n_mod_since_analyze all seem to be reset to 0.
>
>> Can anyone confirm (or refute) that the behavior I see on my Mac
>> (preservation of these values through a restart) is common & expected
>> behavior?
>
> Yeah, in PG those stats would be preserved, at least as long as it's
> a clean shutdown.
Thanks, Tom. A colleague pointed me to a blog post by Michael Vitale that
confirms this bug on AWS and contains more detail:
https://elephas.io/685-2/
Hope this helps someone else
Philip
