Re: Autovacuum on partitioned table (autoanalyze)

On Mon, Aug 16, 2021 at 05:28:10PM -0500, Justin Pryzby wrote:
> On Mon, Aug 16, 2021 at 05:42:48PM -0400, Álvaro Herrera wrote:
> > On 2021-Aug-16, Álvaro Herrera wrote:
> > 
> > > Here's the reversal patch for the 14 branch.  (It applies cleanly to
> > > master, but the unused member of PgStat_StatTabEntry needs to be
> > > removed and catversion bumped).
> > 
> > I have pushed this to both branches.  (I did not remove the item from
> > the release notes in the 14 branch.)
> 
> |    I retained the addition of relkind 'p' to tables included by
> |    pg_stat_user_tables, because reverting that would require a catversion
> |    bump.
> 
> Right now, on v15dev, it shows 0, which is misleading.
> Shouldn't it be null ?
> 
> analyze_count       | 0
> 
> Note that having analyze_count and last_analyze would be an an independently
> useful change.  Since parent tables aren't analyzed automatically, I have a
> script to periodically process them if they weren't processed recently.  Right
> now, for partitioned tables, the best I could find is to check its partitions:
> | MIN(last_analyzed) FROM pg_stat_all_tables psat JOIN pg_inherits i ON psat.relid=i.inhrelid
> 
> In 20200418050815.GE26953@telsasoft.com I wrote:
> |This patch includes partitioned tables in pg_stat_*_tables, which is great; I
> |complained awhile ago that they were missing [0].  It might be useful if that
> |part was split out into a separate 0001 patch (?).
> | [0] https://www.postgresql.org/message-id/20180601221428.GU5164%40telsasoft.com

I suggest the attached (which partially reverts the revert), to allow showing
correct data for analyze_count and last_analyzed.

Arguably these should be reported as null in v14 for partitioned tables, since
they're not "known to be zero", but rather "currently unpopulated".

n_mod_since_analyze | 0
n_ins_since_vacuum  | 0

Justin