>>This is the easiest, and probably the best way to do this.
>>

>>Update yourtable set field1=data1, field2=data2,...;
>>  where uniqfield1=uniqdata1 and uniqfield2=uniqdata2 and uniqfield3=uniqdata3
>>if _tally=0 && No records found, so this is a new record
>>  Insert into yourtable (field1, field2... , uniqfield1, uniqfield2, uniqfield3);
>>    data (data1, data2, ... ,uniqdata1, uniqdata2, uniqdata3)
>>endif

>
>Looks like a good idea.
>
>What if we work with buffered tables? We may still need a candidate index.

Regarding buffered tables, I am not sure, but it has never been an issue for me. Since three fields are involved, you would need a surrugate key as a candidate index, I don't like surrugate keys.