Database Activity Detail for an IMS System view (IDASDTLR)

The Database Activity Detail for an IMS System view provides detailed information about database I/O activity and DL/I calls for a selected IMS subsystem. Statistics are summarized for the selected system.

You can use the IDASDTLR view to recognize and solve N-way data sharing problems resulting from I/O contention or buffer cross-invalidation, and it shows DL/I call and I/O event totals, rates, and average times.

Related topic

Manage-IMS-database-activity

The IDASDTLR view also provides the following information, which is not included in other database activity views.

  • Number of I/Os per DL/I call
  • Number of seconds (or minutes, if interval) during which the data has been collected
  • Number of databases with DL/I calls
  • Number of databases with I/O in the sample period
  • Number of volumes with I/O in the sample period

You can use the information in the IDASDTLR view to interpret the averages, rates, and totals reported in other views.

The IDASDTLR view reports DEDB database activity if the Event Collector parameter DBFPLVL is set to collect DEDB activity, but it does not report MSDB and GSAM database activity or activity caused by background write.

You can hyperlink to the IDASDTLR view from the:

  • Database Activity, Overview option in the IMS Easy Menu (EZIMSR) and the IMS Fast Menu (EZIFASTR)
  • Database Activity Average fields in the DBCTL Dashboard Menu (DBCMDASH)
  • IMS Name field in the IDASSUMR view

IDASDTLR view

 IMS Name................  I9A410CT  Sample seconds..........              5.0
 IMS ID..................       I9A                                            
 Data Sharing Group......      NONE                                            
                                                                              
 --FULL FUNCTION DB I/O--            --- DATABASE CALLS -----                  
 Total        I/O Seconds      0.05  DL/I Call Total Seconds.            0.068
 Average      I/O Time...     0.001  DL/I Call AVG Time......           0.0017
 Read         I/O AVG....     0.002  DL/I Call Rate..........             7.75
 Write        I/O AVG....     0.001  DL/I Call Percent I/O...            71.63
 Read         I/O Rate...      4.17  DL/I Call AVG NBR I/O...            0.744
 Write        I/O Rate...      2.78   DB GU    Rate..........             2.58
 Sync Write   I/O Rate...      2.19   DB GHU   Rate..........             1.19
 Read OSAM XI I/O Rate...      0.00   DB GN    Rate..........             0.00
                                      DB GNP   Rate..........             0.00
 --DEDB DATABASE I/O ----             DB GHN   Rate..........             0.00
 Total        I/O Seconds      0.03   DB GHNP  Rate..........             0.00
 Average      I/O Time...     0.002   DB ISRT  Rate..........             2.78
 Read         I/O AVG....     0.002   DB REPL  Rate..........             0.20
 OTHREAD      I/O AVG....     0.001   DB DLET  Rate..........             0.99
 Read         I/O Rate...      1.59   DB OTHER Rate..........             0.00
 OTHREAD      I/O Rate...      1.59  Databases with calls....                4
                                                                              
 --ALL DATABASE I/0 -----             --- BUFFER POOLS ------                  
 Databases    with I/O...         5  VSAM Bufr Pool Hit Ratio             67.4
 Volumes      with I/O...         8  OSAM Bufr Pool Hit Ratio             90.8

If a database has excessive I/O, a buffer pool may be too small. You can hyperlink from the IDASDTL VSAM Bufr Pool Hit Ratio and the OSAM Bufr Pool Hit Ratio fields to access information you can use to determine whether you need to increase the size of the buffer pool.


 

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