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Block Size Alter 24x7 BA24 steps and sample JCL

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Article ID: 244605

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Updated On:

Products

Datacom/DB

Issue/Introduction

Where is the sample JCL to run Block Size Alter 24x7 (BA24).  What are the steps to run a BA24?

Environment

Release : 15.1

Component : DATACOM/DB

Resolution

The Block Size Alter (BA24) feature runs entirely in the MUF, it moves all rows in an area to a new target area.
The BA24 process is started by running a DDUPDATE 1000 ALTER transaction so there is no specific sample JCL for it.

Here is a summary of the steps to perform a Block Size Alter (BA24):

  1. The MUF startup AREA_BLOCK_SIZE_ALTER must be set to YES, the default is NO.

  2. A DBUTLTY PREINIT is required to be run before the BA24 for the new target area using the new blocksize. You can find the JCL for the PREINIT in documentation section Create the PREINIT Data Set and Store Info in CXX
    //PREINI14 JOB . . . 
    //*-----------------------------------------------------------------**
    //JOBLIB  . . .
    //*-----------------------------------------------------------------**  
    //* ********************************************
    //* ALLOCATE THE TARGET DATA AREA                                    
    //* ********************************************                
    //ALLOC    EXEC PGM=IEFBR14                                      
    //DEM001T  DD DSN=DCMQA.QAMUF4.DEM001.ASOF0604,DISP=(NEW,CATLG),
    //         SPACE=(TRK,(0001,01)),UNIT=(WORK)                    
    //*                                                              
    //* ********************************************                
    //* PREINIT  THE TARGET DATA AREA                                
    //* ********************************************                
    //PREINIT  EXEC PGM=DBUTLTY                                      
    //DEM001   DD DSN=DCMQA.QAMUF4.DEM001.ASOF0604,DISP=(SHR)        
    //SYSIN DD *                                                    
    PREINIT DBID=001,AREA=DEM,BLKSIZE=4096                          
    /*
    //* ********************************************                
    //* ALLOCATE THE TARGET INDEX AREA                              
    //* ********************************************                
    //ALLOC    EXEC PGM=IEFBR14                                      
    //IXX001T  DD DSN=DCMQA.QAMUF4.IXX001.ASOF0606,DISP=(NEW,CATLG),
    //         SPACE=(TRK,(0001,01)),UNIT=(WORK)                    
    //*                                                              
    //* ********************************************                
    //* PREINIT  THE TARGET INDEX AREA                              
    //* ********************************************                
    //PREINIT  EXEC PGM=DBUTLTY                                      
    //IXX001   DD DSN=DCMQA.QAMUF4.IXX001.ASOF0606,DISP=(SHR)        
    //SYSIN DD *                                                    
    PREINIT DBID=001,AREA=IXX,IXXAREA=IXX  
    /*
  3. Start the BA24 process by running a DDUPDATE 1000 ALTER transaction.
    The process runs entirely in the MUF so check the MUF messages for the progress of the BA24 process.
    See documentation section Start the Block Size Alter Process
    Use the following DDUPDATE input:
    //SYSIN   DD  *
    -UPD AREA,areaname(PROD)
    1000 ALTER
    1500 BLOCKSIZE,nnnn
    -END
    /*
    Where nnnn is the new block size and must be the same block size used in the PREINIT.

 

Additional Information

For full documentation see section Performing a Block Size Alter 24x7