>Hi,
>
>Thank for the advise.
>However,my application just do the following below
>
>01) open 03 permanent dbf file in exclusive mode
>02) read 01 permanent dbf file and update the records into the above 01 dbf file
>03) read & update all records every 01 minute.

Maybe the interval sessions appear like 'share' users. Have you tried opening 03 as a shared file?
Terry