Open/Close Statistics

This panel shows information about open and close data set activity and information about Deferred Close activity.


________________ ZOPCL    VTM     O2       V540./C SZ21 09/10/13 13:49:55   2  
>        Help PF1          Back PF3            Up PF7          Down PF8         
> R.K                                                                           
>                                                                               
> H-HISTORICAL                                                                  
=============================================================================== 
>                            OPEN/CLOSE STATISTICS                              
                                                                                
 OPCL                                                                           
+ Collection Interval:  REALTIME                         Start:  09/10 13:46:49 
+ Report Interval:       4 sec                             End:  09/10 13:49:55 
+                                                                               
+ Maximum Number of Open Datasets (DSMAX)      =    20000                       
+ Checkpoints to Pseudo-Close (PCLOSEN)        =        5                       
+ Elapsed Time to Pseudo-Close (PCLOSET)       =       10                       
+ Current Number Open Datasets                 =      154                       
+ High Water Mark Open Datasets                =      154                       
+ High Water Mark Not-in-use Datasets          =      150                       
+ Current Number Not-in-use Datasets           =      150                       
+                                                                               
+                                    TOTAL  INTERVAL  /SECOND  /THREAD  /COMMIT 
+                                 QUANTITY  QUANTITY  (    4)  (    1)  (    6) 
+                                 --------  --------  -------  -------  ------- 
+ Not-in-use Datasets Requested      58047         7     1.75     7.00     1.17 
+ Not-in-use Datasets Closed             0         0      .00      .00      .00 
+ Datasets Converted to Read-Only       94         0      .00      .00      .00 
===============================================================================

Navigation

For additional information about

Near-term history activity, select option H-HISTORICAL at the top of the panel.
other topics, use the PF keys.

Fields

Collection Interval: Shows the REALTIME to indicate that you are looking at the realtime version of this panel and not at the corresponding near-term history panel. The collection interval and the report interval are the same in this panel.
Start: The start time of the report interval currently displayed.
Report Interval: The time in the last cycle (for example, between two presses of the Enter key).
End: The end time of the report interval currently displayed.
Maximum Number of Open Datasets (DSMAX): The value specified for the installation parameter DSMAX. Db2 uses this value to determine when the drain process should be initiated to close unused data sets.
Checkpoints to Pseudo-Close (PCLOSEN): The number of consecutive checkpoints that a data set or partition must go through since it was last updated before being selected for pseudo-close, that is, the state changed from read-write to read-only.
Elapsed Time to Pseudo-Close (PCLOSET): The time in minutes that must elapse since a data set or partition was last updated before it can be selected for pseudo-close.
Current Number Open Datasets: The current number of open data sets.
High Water Open Datasets: The maximum number of data sets open at any one time since Db2 was started.
High Water Mark Not-in-use Datasets: The maximum number of pagesets specified with CLOSE(YES) that are not in use but are not physically closed.
Current Number Not-in-use Datasets: The current number of open pagesets specified with CLOSE(YES) that are not in use but are not physically closed.

For each of the following fields, the following statistics values are provided:

TOTAL QUANTITY: Total quantity, which reflects the amount of activities since DB2 was started.
INTERVAL QUANTITY: Interval quantity, which reflects the amount of activities during the last cycle.
/SECOND: Rate per second during the last cycle. The number under /SECOND (in parentheses) is the number of seconds in the interval.
/THREAD: Rate per thread during the last cycle. The number under /THREAD (in parentheses) is the number of Create Threads during the interval.
/COMMIT: Rate per Commit during the last cycle. The number under /COMMIT (in parentheses) is the number of commit requests (including abort requests) during the interval.

Not-in-use Datasets Requested: Number of requests to open a data set that was on the deferred close queue. When this occurs, a physical data set Open is not necessary.
Not-in-use Datasets Closed: Number of not-in-use data sets that were closed because the total number of open data sets reached the Deferred Close threshold. The Deferred Close threshold is based on the smaller of the values of DSMAX or the MVS DD limit.
Datasets Converted to Read-Only: The number of infrequently updated data sets converted from read-write to read-only (pseudo-close). The SYSLGRNG entry is closed at this time.