Re: local selectivity estimation - computing frequency of predicates

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

"Avdhoot Kishore Saple" <Avdhoot_Saple(at)infosys(dot)com> writes:
> How to compute the frequency of predicate (e.g. Salary > $70000) in an
> SQL query from a DB's pre-defined indexes?". I'm specifically looking at
> how to retrieve information about indices (like number of pages at each
> level of index, range of attribute values etc.)

I don't think what you're looking for is exposed anywhere.  Postgres
doesn't rely on indexes for statistical information anyway; the
pg_statistic system catalog (see also pg_stats view) is used for that.

			regards, tom lane