The index expression is a large string..

I'm using:

BINTOC(table1.primarykey) + BINTOC(table1.secondarykey) + BINTOC(table2.primarykey) + BINTOC(table2.secondarykey) + BINTOC(table3.primarykey) + BINTOC(table3.secondarykey)

Are you saying I can get the same result from a different, smaller index expression but still reference these three tables and all 6 fields?

Thanks.