Defining an area as COVERED without recycling Datacom MUF

Products

• Datacom/AD
• Datacom
• Datacom/DB
• DATACOM - AD

Issue/Introduction

The COVERED cards are used during the Datacom Multi-User Facility (MUF) startup to identify the index or data areas that are to remain in storage while they are open. So "covering" an area while MUF is up and running requires a MUF recycle. Is there any way to cover an area without recycling the Datacom MUF region?

Environment

Release : 15.1

Component :

Resolution

In order to cover an index or data area without recycling the MUF, you can use the COVERED_ADD console command.

As other Datacom console commands, it can be issued from the z/OS console, running a DBUTLTY COMM function or executing an SQL query (e.g. via DBSQLPR). 

For example, covering IXX area of DBID 001:

• via MVS MODIFY (F) command:
  F jobname,COVERED_ADD 001,IXX,105,F,0
  where jobname is the MUF region jobname
• via DBUTLTY COMM function:
  COMM OPTION=CONSOLE,OPTION2='COVERED_ADD 001,IXX,105,F,0'
• via SQL query (e.g. using DBSQLPR):
  INSERT INTO SYSADM.SQL_CONSOLE (MUF_NAME, CONSOLE_COMMAND ) VALUES ('mufname', 'COVERED_ADD 001,PMF,105,F,0'); 

The MUF should return a message like:

DB00608I - yyyyyyy COMPLETE - COVERED_ADD 001,IXX,105,F,0

where yyyyyyy can be:
CONSOLE
DBUTLTY COMM CONSOLE
SQL_CONSOLE
depending on the method used to issue the command.

The area will be loaded in memory at the next open.

Additional details can be found on the COVERED_ADD documentation page.

Additional Information

Because this function will only take effect when the areas are opened, if they are currently open, they need to be closed first. You can use the CLOSE or ACCESS STATUS=OFF, CLOSE, and ACCESS STATUS=WRITE functions as needed to ensure the area is closed appropriately. If using the area in CICS, the URT there must be closed first.

For example, you can close it (better when there is no activity), using a DBUTLTY with the following SYSIN cards:

//SYSIN    DD  *                      
ACCESS STATUS=OFF,DBID=001,USERS=FAIL 
COMM OPTION=CLOSE,DBID=001            
/*        

followed by another DBUTLTY step with:

//SYSIN    DD  *                      
ACCESS STATUS=WRITE,DBID=001
/*   

Please note that this last step must be executed even if the first one failed due to active users on DBID 001 (U0004 abend).                        

At the next request, DBID 001 will be automatically opened (in COVERED mode).

Please see also "DB00605E or RC 94(129) returned to COVERED_ADD MUF command" article.