Controlling migrated data sets in CICS

The CICS® VT GLUE is called VIDCGLUE, and is automatically invoked every time a migrated data set is processed. Calls initiated from CICS terminals such as CEMT or CECI are processed by VIDCGLUE.

Calls from application programs that use the systems programming interface SET FILE or SET DATA SET are also processed by VIDCGLUE. This means that CICS file control calls have the same effect in CICS VT as they do in CICS. For example, here is the response to a CEMT transaction inquiring on the status of the file KSDS05:

Figure 1. CICS CEMT inquire file results
 
 I FILE(KSDS05)                                             
  STATUS:  RESULTS - OVERTYPE TO MODIFY                       
  Fil(VIDKSDS ) Vsa Ope Ena Rea Upd Add Bro Del     Sha      
         Dsn(VID.KSDS05                                )

The CICS VT VTMD supplied transaction, described in VTMD - displaying the CICS VT DST, displays the status of migrated files in CICS. The response to the VTMD transaction is shown in Figure 2:

Figure 2. CICS VTMD file definition list screen
  
          08/31/11     ==>  CICS VT File Definitions  <==     16:24:22          
                                                                                
  Filename  DIM name   Org   Status            MStatus Operations    Compare    
  KSDS01    KSDS01           ENA INI           ACT     R U A B D     REP   N    
  KSDS02    KSDS02           ENA INI           ACT     R U A B D     REP   N    
  KSDS02P   KSDS02AI         ENA INI           ACT     R U A B D     REP   N    
  KSDS03    KSDS03           ENA INI           ACT     R U A B D     REP   N    
  KSDS03P1  KSDS03P1         ENA INI           ACT     R U A B D     REP   N    
  KSDS04    KSDS04           ENA INI           ACT     R U A B D     REP   N    
  KSDS05    KSDS05           ENA INI           ACT     R U A B D     REP   N    
  KSDS05P1  KSDS05P1         ENA INI           ACT     R U A B D     REP   N    
  KSDS05P2  KSDS05P2         ENA INI           ACT     R U A B D     REP   N    
  KSDS05P3  KSDS05P3         ENA INI           ACT     R U A B D     REP   N    
  KSDS05P4  KSDS05P4         ENA INI           ACT     R U A B D     REP   N    
  KSDS06    KSDS06           ENA INI           ACT     R U A B D     REP   N    
  KSDS06P1  KSDS06P1         ENA INI           ACT     R U A B D     REP   N    
  KSDS07    KSDS07           ENA INI           ACT     R U A B D     REP   N    
  KSDS07P1  KSDS07P1         ENA INI           ACT     R U A B D     REP   N    
  KSDS08    KSDS08           ENA INI           ACT     R U A B D     REP   N    
  KSDS09    KSDS09           ENA INI           ACT     R U A B D     REP   N    
  KSDS10    KSDS10           ENA INI           ACT     R U A B D     REP   N    
  More                                                                          
  PF3=end PF7=back PF8=fwd                          SYSID=S650 APPLID=CICSTS32  
                                                                                

The status of the file according to the CEMT transaction is always consistent with the file status according to CICS VT, because CICS VT intercepts CEMT and CECI transactions and updates the CICS VT file status when necessary. This means that you have the same control over migrated files as you do with non-migrated files. For example, assume that you issue the CICS command to close the data set:

CEMT SET FI(KSDS05) Clo 

When you run the transaction VTMD, you get the following results:

Figure 3. VTMD transaction results
 
          08/31/11     ==>  CICS VT File Definitions  <==     16:24:45          
                                                                                
  Filename  DIM name   Org   Status            MStatus Operations    Compare    
  KSDS01    KSDS01           ENA INI           ACT     R U A B D     REP   N    
  KSDS02    KSDS02           ENA INI           ACT     R U A B D     REP   N    
  KSDS02P   KSDS02AI         ENA INI           ACT     R U A B D     REP   N    
  KSDS03    KSDS03           ENA INI           ACT     R U A B D     REP   N    
  KSDS03P1  KSDS03P1         ENA INI           ACT     R U A B D     REP   N    
  KSDS04    KSDS04           ENA INI           ACT     R U A B D     REP   N    
  KSDS05    KSDS05     KSDS  UNE               ACT     R U A B D     REP   N    
  KSDS05P1  KSDS05P1         ENA INI           ACT     R U A B D     REP   N    
  KSDS05P2  KSDS05P2         ENA INI           ACT     R U A B D     REP   N    
  KSDS05P3  KSDS05P3         ENA INI           ACT     R U A B D     REP   N    
  KSDS05P4  KSDS05P4         ENA INI           ACT     R U A B D     REP   N    
  KSDS06    KSDS06           ENA INI           ACT     R U A B D     REP   N    
  KSDS06P1  KSDS06P1         ENA INI           ACT     R U A B D     REP   N    
  KSDS07    KSDS07           ENA INI           ACT     R U A B D     REP   N    
  KSDS07P1  KSDS07P1         ENA INI           ACT     R U A B D     REP   N    
  KSDS08    KSDS08           ENA INI           ACT     R U A B D     REP   N    
  KSDS09    KSDS09           ENA INI           ACT     R U A B D     REP   N    
  KSDS10    KSDS10           ENA INI           ACT     R U A B D     REP   N    
  More                                                                          
  PF3=end PF7=back PF8=fwd                          SYSID=S650 APPLID=CICSTS32  

The file definition list screen shows that KSDS05 has been changed to UNE. This means that CICS VT will not process calls for this data set because it has been disabled.

To be able to change the status of a file from a CICS perspective, the VSAM data set associated with the file control entry must exist. You can associate any VSAM data set with the file control entry providing that the file is always accessed by CICS VT.


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Timestamp icon Last updated: Monday, 10 February 2014


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