Re: Optional skipping of unchanged relations during ANALYZE?

>
> * A brand new empty table is analyzed (since it has no statistics).
> * Re-running on an empty table analyzes again, because there are still no
> pg_statistic rows.
> * A table with data but no statistics is analyzed.
> * Re-running after statistics exist causes the table to be skipped.
> * If a new column is added and lacks statistics, the table is analyzed
> again.
> * After statistics are created for that column, subsequent runs skip the
> table.
> * If statistics are manually deleted or effectively lost (e.g., crash
> recovery scenarios affecting stats tracking), the table is analyzed again.
>
> Repeated runs therefore converge toward a no-op once all relations have
> complete statistics.
>
> Regression tests are included.
>
> As discussed earlier in the thread, I plan to start a new discussion and
> patch series for a separate ANALYZE (MODIFIED_STATS) option that would
> reuse autoanalyze-style thresholds. I believe keeping MISSING_STATS_ONLY
> and MODIFIED_STATS as separate, clearly defined options makes the semantics
> easier to reason about.
>
> I would greatly appreciate further review and feedback on this version.
> Thank you all for the detailed guidance and suggestions so far — especially
> regarding reuse of examine_attribute() and alignment with vacuumdb
> behavior. This process has been very educational for me.
>
>
>
A few notes:

- attnum variables can be of type AttrNumber
- The SearchSysCache3 lookup can't assume inh = false. Partitioned tables
will ONLY have inh = true. Inheritance parents will have both.
- Same inh concerns for extended stats.