Scott Marlowe <scott.marlowe@ihs.com> writes:
> Since postgresql 7.2.1 refuses to make an index of any kind other than
> btree, what is the answer? no indexes? While single column indexes may
> seem wasteful, remember that the boole may be stored in a table that has
> very large tuples, and a sequential scan of such a table could be quite
> slow, or there may be a situation where a tiny percentage of the booles
> are one setting while most are the other, like an approval system for
> online content.
You could use a partial index for the latter case. If the column is
about fifty-fifty then any kind of index is a waste of space...
regards, tom lane