Re: ANALYZE ONLY

On Wed, 21 Aug 2024 at 06:41, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> I like trying to use ONLY somehow.

Do you mean as an ANALYZE command option, i.e. ANALYZE (only) table;
or as a table modifier like gram.y's extended_relation_expr?

Making it a command option means that the option would apply to all
tables listed, whereas if it was more like an extended_relation_expr,
the option would be applied per table listed in the command.

1. ANALYZE ONLY ptab, ptab2; -- gather stats on ptab but not on its
partitions but get stats on ptab2 and stats on its partitions too.
2. ANALYZE ONLY ptab, ONLY ptab2; -- gather stats on ptab and ptab2
without doing that on any of their partitions.

Whereas: "ANALYZE (ONLY) ptab, ptab2;" would always give you the
behaviour of #2.

If we did it as a per-table option, then we'd need to consider what
should happen if someone did: "VACUUM ONLY parttab;". Probably
silently doing nothing wouldn't be good. Maybe a warning, akin to
what's done in:

postgres=# analyze (skip_locked) a;
WARNING: skipping analyze of "a" --- lock not available

David