Re: Statistics and selectivity estimation for ranges

It looks like there are still some problems with this patch.
 CREATE TABLE foo(ir int4range); insert into foo select 'empty' from generate_series(1,10000); insert into foo select
int4range(NULL,g, '(]')   from generate_series(1,1000000) g; insert into foo select int4range(g, NULL, '[)')   from
generate_series(1,1000000)g; insert into foo select int4range(g, ((g*1.01)+10)::int4, '[]')   from
generate_series(1,1000000)g; CREATE TABLE bar(ir) AS select * from foo order by random(); ANALYZE bar;
 

Now: EXPLAIN ANALYZE SELECT * FROM bar   WHERE ir @> int4range(10000,20000);

The estimates are "-nan". Similar for many other queries.

And I have a few other questions/comments:

* Why is "summ" spelled with two "m"s? Is it short for "summation"? If
so, might be good to use "summation of" instead of "integrate" in the
comment.

* Why does get_length_hist_frac return 0.0 when i is the last value? Is
that a mistake?

* I am still confused by the distinction between rbound_bsearch and
rbound_bsearch_bin. What is the intuitive purpose of each?

* You use "constant value" in the comments in several places. Would
"query value" or "search key" be better?

Regards,Jeff Davis