>I want to maximize the speed of performing calculations in related tables. I will be performing a REPLACE on every record in the child table based on values in the Parent record. Any thoughts on the best performers ?
>
>1) Using Set Relation to 'automate' finding records in child tables
>
>2) Using Set Filter to 'manually' SKIP thru records in child tables based on Parent key.
>
>3) Using Scan For in child table based on Parent key.
>
>4) Using good old fashion Seek in the Child table based on Parent key.

Hi Peter,
First of all I think a REPLACEMENT for REPLACE would be faster. If calculated and replaced fields won't be edited setting a view would be the fastest. If in your case REPLACE is a necessity :
1) Set filter is worst. I better think this command had never existed. If you use it, you would add extra workarounds for optimization. ie: set order tag and locate - instead of go top or set order tag descending and locate for go bottom... etc.
2) Set relation was good in old days. But in buffering modes you don't get your relations as simple.
3) scan...endscan is highyly optimized, but *for* slows down it.
4) Seek as in good old days still is the fastest. Combining seek and scan while...endscan could be best performance.

But better yet instead of batch processing on a set of records, updating during data entry (valid, lostfocus, interactivechange, programmatic change etc.) could be the fastest for it would require much less update.
Cetin