Re: Statistics Import and Export

On Thu, Dec 19, 2024 at 09:23:20PM -0800, Jeff Davis wrote:
> On Fri, 2024-12-13 at 00:22 -0500, Corey Huinker wrote:
> > Per offline conversation with Jeff, adding a --no-schema to pg_dump
> > option both for completeness (we already have --no-data and --no-
> > statistics), but users who previously got the effect of --no-schema
> > did so by specifying --data-only, which suppresses statistics as
> > well.
> >
> > 0001-0005 - changes to pg_dump/pg_upgrade
>
> Attached is a version 36j where I consolidated these patches and
> cleaned up the documentation. It doesn't make a lot of sense to commit
> them separately, because as soon as the pg_dump changes are there, the
> pg_upgrade test starts showing a difference until it starts using the -
> -no-data option.
>
> The biggest functional change is the way dependencies are handled for
> matview stats. Materialized views ordinarily end up in
> SECITON_PRE_DATA, but in some cases they can be postponed to
> SECTION_POST_DATA. You solved that by always putting the matview stats
> in SECTION_POST_DATA.
>
> I took a different approach here and, when the matview is postponed,
> also postpone the matview stats. It's slightly more code, but it felt
> closer to the rest of the structure, where postponing is a special case
> (that we might be able to remove in the future).

I am confused by this:

Add options --with-statistics/--no-statistics to pg_upgrade
to enable/disable transferring of statistics to the upgraded
cluster. The default is --with-statistics.

If statistics is the default for pg_upgrade, why would we need a
--with-statistics option?

Also, I see a misspelling:

+ printf(_(" --no-statisttics do not import statistics from old cluster\n"));
--

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

Do not let urgent matters crowd out time for investment in the future.