5. FILES › 5.13 DB2 Buffer Pool Activity (DBPDSB) File › 5.13.3 Usage Considerations

5.13.3 Usage Considerations

This section identifies the special considerations or
techniques related to using the DBPDSB file.  Additionally,
several retrieval examples are provided to facilitate the use
of this file.

In the examples, we use a SAS macro to specify the DD name
part of the CA MICS file name.  These macros are a standard
part of CA MICS and are available for all files.  The macro
name has the form _iiit, where "iii" is the Information Area
name and "t" is the timespan.  In addition, many of the
examples use the _fffSUM macro, where "fff" is the file
identifier, to summarize the data as indicated by the _BY and
_BREAK macro definitions.

Special Considerations/Techniques

 1.  The following data elements only have meaning when using
     the DBPDSBnn file in the DETAIL timespan, in that they
     lose significance once summarization has been performed.
     These data elements should only be referenced when using
     the DBPDSBnn file in the DETAIL timespan.

     DB2ISEQ - Instrumentation Sequence Number

 2.  Care must be exercised in using the special date and
     time data elements contained in each CA MICS file.  As
     the file's granularity increases in higher timespans,
     certain fields lose significance and should not be
     referenced.

     o HOUR should not be used in MONTHS and YEARS.
     o DAY and DAYNAME should not be used in WEEKS, MONTHS,
       or YEARS.
     o WEEK should not be used in MONTHS or YEARS.
     o MONTH should not be used in YEARS.

 3.  The data elements STARTTS and ENDTS have different
     meanings when used in the DETAIL timespan versus their
     meaning in the DAYS, WEEKS, MONTHS, and YEARS timespans.
     The ENDTS and STARTTS, when appearing in the DAYS,
     WEEKS, MONTHS, and YEARS timespans, indicate the span of
     time over which the data has been summarized with
     STARTTS indicating the lowest date and time and ENDTS
     indicating the greatest date and time for the summarized
     data.

Retrieval Examples

 1.  Plot the Get Pages used by DB2 Buffer Pool over the last
     4 weeks by week.

     DATA TEST1;
     SET &DBPW..DBPDSB01
         &DBPW..DBPDSB02
         &DBPW..DBPDSB03
         &DBPW..DBPDSB04
         ;
     DATE=DATEPART(STARTTS);
     FORMAT DATE DATE7.;
     %LET BY = DB2ID DB2PID WEEK ;
     %LET BREAK = WEEK ;
     PROC SORT DATA=TEST1 OUT=TEST1;  BY &BY;
     DATA TEST1;
     SET TEST1;
     %DSBSUM;
     PROC PLOT DATA=TEST1;
     BY DB2ID DB2PID;
     PLOT DSBDBPU*WEEK;
     TITLE
      'DB2 Database Page Updates By Buffer Pool By Week';

 2.  Print the several indicators of buffer pool activity for
     last week, zone 1 (prime shift).  Number of Buffer Pool
     Expansions, Buffer Pool Data Sets Opened, Number of
     Active Buffers In Buffer Pool, System pages Written to
     DASD, and Prefetch Request Disabled due to unavailable
     buffer resource.

     DATA TEST2;
     SET _DB2W.DBPDSB01;
     IF ZONE=1;
     PROC PRINT DATA=TEST2;
     VAR SYSID DB2ID DB2PID DSBSBPE DSBBPSO DSBABBP DSBSPWR
         DSBSPDF;
     TITLE  'DB2 BUFFER POOL PERFORMANCE INDICATORS FOR';
     TITLE2 'LAST WEEK IN ZONE 1 (PRIME SHIFT)';