Can you add indexes in your tables? I would create a compound index for this...

>Thanks for the reply but that still give the same error " Invalid Key length". I broke the query in two parts and still it gave me the same error. If I give only two matching fields, it works fine but as soon as I add the third comparing field, it gives me the same error, the error number is "Error 112". It has something to do with the Index key. I have no index keys in any of the tables
>
>Like this work fine :-
>
>SELECT hdr.claim_num, ;
>hdr.pat_lname, hdr.pat_fname, ;
>hdr.batch_num, ;
>rpt.claim_num, rpt.end, rpt.start, ;
>rpt.units, rpt.billed, rpt.fee, rpt.prov, ;
>rpt.mod, rpt.code ;
>FROM _4_claim_temp_header hdr, batch_rpt rpt;
> where;
> rpt.claim = hdr.ins_policy and ;
> rpt.pat_fname = hdr.pat_fname
>
>but this doesnot work and give me error 112
>
>SELECT hdr.claim_num, ;
>hdr.pat_lname, hdr.pat_fname, ;
>hdr.batch_num, ;
>rpt.claim_num, rpt.end, rpt.start, ;
>rpt.units, rpt.billed, rpt.fee, rpt.prov, ;
>rpt.mod, rpt.code ;
>FROM _4_claim_temp_header hdr, batch_rpt rpt;
> where;
> rpt.claim = hdr.ins_policy and ;
> rpt.pat_fname = hdr.pat_fname and ;
> rpt.pat_lname = hdr.pat_lname and ;
> rpt.ssn = hdr.enrollee
>
>
>Thanks
>bharat