Re: Custom opclass for column statistics?

Ancoron Luciferis <ancoron(dot)luciferis(at)googlemail(dot)com> writes:
> I've been wondering whether it is possible somehow to have the standard
> column statistics to respect a certain operator class?

In principle, pg_statistic can represent stats for a non-default opclass.
Teaching ANALYZE to collect such stats when appropriate, and then teaching
the planner to use them when appropriate, is left as an exercise for the
reader.

I think the "when appropriate" bit is actually the hardest part of that.
Possibly, if you were satisfied with a relatively manual approach,
you could proceed by using CREATE STATISTICS to declare interest in
keeping standard stats for a non-default sort order. Not sure what to
do if you want it to be automatic, because I don't think people would
hold still for having ANALYZE collect stats for any random non-default
opclass automatically. Maybe a new opclass property?

regards, tom lane