IBM SC33-1683-02 - Manual (Page 704)

Performance data sections
Each performance data section is made up of a string of field connectors, followed
by one or more performance data records. All of the performance records produced
by a single CICS run have the same format, and each record is, by default, 664
bytes long. However, the length of the performance records changes if you add
user data at user EMPs, or if you exclude any system-defined data from the
monitoring process. All of the system-defined data fields in the performance records
are described in the
CICS Performance Guide. The format of the performance data
section is shown in Figure 89.
Relationship of the dictionary record to the performance records
Following the performance records’ SMF product section, and before the
performance records themselves, is a string of field connectors. The purpose of
the field connectors is to tell you which fields are going to occur in the performance
records produced by this CICS run. Each field connector corresponds to one field in
each of the succeeding performance records. The first field connector corresponds
to the first field, the second to the second field, and so on. Each field connector
also corresponds to a single dictionary entry in the associated dictionary record: the
connector value is equal to the value of CMODCONN in the corresponding
dictionary entry. In this way, each performance record field is connected to the
dictionary entry that describes it. A useful technique for calculating the offset of a
particular dictionary entry is to take the connector, subtract one, and multiply the
result by the length of a single dictionary entry.
Thus, the string of field connectors is the key to the dictionary. And without the
dictionary, reporting and analysis programs cannot interpret the performance data.
The successive performance records can be regarded as rows in a table, with each
column corresponding to one type of field within the records. Each field connector
then describes the contents of one column. This view of the data is helpful when
designing tabular reports, which are often arranged in this way.
Figure 90 on page 673 illustrates the relationship between the dictionary record, the
field connectors, and the performance records.
SMF Header SMF Product Section Performance Data Section
Field Performance Performance Performance Performance
Connectors Record 1 Record 2 Record 3 Record n
Data for Data for Data for Data for Data for Data for
field 1 field 2 field 3 field 4 field 5 field n
Figure 89. Format of the performance data section
monitoring record formats
672 CICS TS for OS/390: CICS Customization Guide