On Sat, 18 Oct 2014 11:34:18 -0400, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > If the comparison value is outside the range recorded in the histogram, > and there's a suitable index available, the planner uses the index to > find out the actual column min or max rather than believing the histogram > completely. See get_actual_variable_range(). Substituting the first histogram value with 1 (the lowest value in the column/index) and redoing the calculation give the same numbers as the EXPLAIN ANALISE does. But how so that the selectivity is now not capped to 0.0001? Without the index I couldn't get an estimate lower than 100 rows, but with the index the estimates go all the way down to 1. > Possibly this behavior ought to be mentioned in the docs ... It would help a lot :) Regards, Mladen Marinović -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
