Performance data files

You can generate database files from the collection objects maintained by Collection Services. Use this topic to find the names, descriptions and attributes of these database files.

Performance data is a set of information about the operation of a system (or network of systems) that can be used to understand response time and throughput. You can use performance data to make adjustments to programs, system attributes, and operations. These adjustments can improve response times and throughputs. Adjustments can also help you to predict the effects of certain changes to the system, operation, or program.

Collection Services collects performance data into a management collection object (*MGTCOL). The Create Performance Data (CRTPFRDTA) command processes data from that collection object and stores the result into performance database files. The database files are divided into the following categories:

Performance data files containing time interval data

These files contain performance data that is collected each interval. To understand where the data in these files comes from, see system category and file relationships. When viewing these files, you might also find the file abbreviations useful.

Configuration data files

Configuration data is collected once per session. To understand where the data in these files comes from, refer to system category and file relationships. You can find the QAPMCONF, QAPMHDWR, and QAPMSBSD files in the configuration data files.

Trace data files

Trace data is collected only when you choose to do so. You can find the QAPMDMPT file in the trace data files.

Additional field information such as number of bytes and buffer position is available by using the Display File Field Description (DSPFFD) command available on the system. For example, type the following on any command line:

DSPFFD file(QSYS/QAPMCONF)