> Following the formula outlined
> in http://www.postgresql.org/docs/8.3/static/row-estimation-examples.html
> Both gradrate 10 and gradrate 11 would fall in the first bucket.
> Shouldn't the row estimation be:
> (11 - 8) / (33 - 8) / 10 * 1302 = 15.624
> and
> (10 - 8) / (33 - 8) / 10 * 1302 = 10.
Dne 20.3.2011 08:20, Reynold Xin napsal(a):
> Following the formula outlined
> in http://www.postgresql.org/docs/8.3/static/row-estimation-examples.html
>
> Both gradrate 10 and gradrate 11 would fall in the first bucket.
>
> Shouldn't the row estimation be:
>
> (11 - 8) / (33 - 8) / 10 * 1302 =
I have a rankings table and it has 1302 rows in total. I am a bit confused
by how postgres (8.2.11) calculates the cardinality for this rankings table
based on < predicates on gradrate attribute.
select histogram_bounds from pg_stats where attname = 'gradrate' and
tablename = 'rankings';
