>Another thing you can do is anticipate all the possible orders
>and provide indexes for them so that the optimiser has something
>better to choose from.

Alternatively: You should also try to _remove_ the index that is used for
sorting (if this does not also remove indexes used in the WHERE
clause. Even 'bending' the query to avoid ordering by an index can be a
good thing. IB/Fb usually sorts quite fast, but when it tries to use an
index for the ORDER BY it often slows down.
YMMV

--
Aage J.