order by x DESC, y ASC indexing problem

Hello,

I saw a posting regarding this issue in august, with no solution...

How to have the planner use an index in the case of a query like :

SELECT * FROM TABLE1 ORDER BY X DESC, Y ASC;

(X is a date and Y a varchar)

What would that index be?

Is there a function I can use, to invert x (the date), so that I can 
make a query / index set like :



CREATE INDEX INDEX1 ON TABLE 1 (INVERT(X), Y ASC);
SELECT * FROM TABLE1 ORDER BY INVERT(X) ASC, Y ASC;


Wouldn't it be great to have a mySQL, SAPDB-like syntax of the sort :

CREATE INDEX INDEX1 ON TABLE 1 (X DESC, Y ASC);


Thanks,


vincent