Zdravko Balorda wrote:
> this is probably an old issue but I'm not all that experienced.
>
> I wonder if an index can be accessed rather directly, as to speed up
> a query like "select count(distinct())", by simply calculating the
> number of branches (leaves) an index has. Or at least to skip sorting.
Afraid not. Have a search of the archives for discussion on "mvcc
visibility indexes" for lots on this.
--
Richard Huxton
Archonet Ltd