Agree with Rob, OleDB should in almost all cases be faster than ODBC, so start with that one. Secondly, a plain sql statement is of course faster than a more complex one so it could be a good thing to do all the transformation of data (like date,cast,substr functions) in a load statement instead (ie first store the plain data in qvd and then load and transform the data from the qvd file). It is always a matter of testing and desciding if it is total Qv load time or db select time that is most important.
If you go outside the Qlikview world I guess you'll find many posts on oracle forums about what function beats a similiar.
