Subject Re: [ib-support] Index on Boolean-Col
Author Nando Dessena

> Even a index with very low selectivity is good for selects.
> With a multi-million-rows table, a index for a column with maybe
> 10 unique values could save your hours of retrival time.

you are perfectly right; I wish the tendency to discourage people from
using low selectivity indices in every possible situation would stop.
It would be much more true to say that low selectivity indices are bad
for small/medium tables for the fact that they can get in the way of the
optimizer in joins.