The SET PC_SAMPLING command enables the collection of program
counter sampling data. After you enter the GO command with
program counter sampling enabled, the Collector samples the
program counter (PC) every 10 milliseconds and records each
observed program counter value in the performance data file. You
can change the sampling interval with the /INTERVAL:n qualifier.
You must collect stack PC information if you want to use a /MAIN_
IMAGE, /CUMULATIVE or /STACK_DEPTH qualifier with the PLOT or
TABULATE command in the Analyzer.