Re: Optional skipping of unchanged relations during ANALYZE?

>> I am wondering if we should take the current SQL used by vacuumdb to
>> find missing stats and perform direct syscache lookups in C?
>
>
> So....about that. The exiting missing-stats-only queries test for a corresponding
> pg_statistic_ext_data row for any pg_statistic_ext row that meets the relation filters,
> but at this very moment we can restore all types of extended stats _except_ expressions.
> That functionality could make it into 19, but if it doesn't we're going to have to adjust
> vacuumdb to probe pg_statistic_ext.stxkeys for expression indexes and look for
> matching stxdexprs elements. I agree that those matches are better done with
> syscache lookups, but the SQL that we're treating as a spec might be a moving
> target in the near future.

Eventually we will want vacuumdb to use the "ANALYZE (MISSING_STATS)" command
directly, rather than the SQL, but until the restore functionality
works for extended stats
of expressions, we will need to keep those separated. Did I understand
that correctly?

--
Sami Imseih
Amazon Web Services (AWS)