Thanks Jason,
I use filters on lookup TIBOTable and generally the result in less than one hundred rows.
For these tables I use locate to spécifically find a record
For the other TIBOTable (on which I insert or update) I use a gotokey to find the record

Would it be better (in terms of performance) to use IndexFieldName to sort on the fields involved in and use a SQLWhere string to limit the result ? (either to the range or to the record)

With large tables, every things limiting the network bandwidth will be useful
Thanks