Library /sys$common/syshlp/pca$help.hlb CANCEL, DATAFILE, Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    The CANCEL DATAFILE command closes the current performance data
    file. The Collector does not record data in that file when data
    collection starts. Instead, it uses the default data file or the
    data file you establish with a subsequent SET DATAFILE command.
    The Analyzer does not read or process data until another SET
    DATAFILE command is entered.