>Expensive or expansive?
>
>>C(10) is more expansive than Integer. I currently decided to use composite key.

Here is SQL:

SELECT Filingdate.rcode, Filingdate.town, Filingdate.record_fm, ;
  Filingdate.record_to, Filingdate.landct_fm, Filingdate.landct_to,  ;
Filingdate.calmnth, Filingdate.mdflag, Filingdate.nodata,  ;
Filingdate.notes, Filingdate.ddflag, Filingdate.dsid, Filingdate.state, ;
 Filingdate.extryear, Filingdate.extrweek, Filingdate.ccode ;
FROM support!filingdate ;
WHERE Filingdate.dsid BETWEEN ?lnIdLow AND ?lnIDHigh  ;
 AND state+extryear+extrweek BETWEEN ?lcStWkLow AND ?lcStWkHIgh ;
ORDER BY Filingdate.extryear DESC, Filingdate.extrweek DESC,  Filingdate.rcode, Filingdate.town

Show plan shows:
Using index tag Deleted to rushmore optimize table filingdate
Rushmore optimization level for table filingdate: partial

Why StateWeek and DsID indexes are not used? I have StateWeek index with State+ExtrYear+ExtrWeek and DsID indexes...

Also how can I change BETWEEN command to BETWEEN function?