BAM internal tracing occurs for the duration of the data set's access by the application program, from OPEN until CLOSE. Tracing starts when the BAM OPEN executor determines that you requested OPEN/CLOSE/EOV work area tracing. You do not have to start GTF. BAM creates internal trace records until the data set's DCB is closed. The BAM internal trace table is destroyed (with FREEMAIN) during DCB CLOSE processing.