The initialization phase for HALDB Online Reorganization

You start the online reorganization of a HALDB partition using the INITIATE OLREORG command.

During the initialization phase, IMS updates the RECON data sets to establish the ownership of the online reorganization by the IMS system that is performing the online reorganization. This ownership means that no other IMS system can perform a reorganization of the HALDB partition until the current online reorganization is complete or until ownership is transferred to another IMS system. IMS adds the M-V (and Y) DBDSs to the RECON data sets if those DBDS records do not already exist. IMS also adds the M-V (and Y) DBDSs to any existing change accumulation groups and DBDS groups that include the corresponding A-J (and X) DBDSs.

Before online reorganization begins for a HALDB partition, there is a single set of active data sets for the HALDB partition. These active data sets are the input data sets for the copying phase. There might also be a set of inactive data sets from a prior online reorganization that are not used by IMS application programs.

During the initialization phase, IMS evaluates each of the inactive data sets to ensure that it meets the requirements for output data sets. If any of the output data sets does not exist, IMS creates it automatically during this phase.

At the end of the initialization phase, IMS treats the original active set of data sets as the input set and the inactive data sets as the output set. This use of the input and output sets of data sets is represented by the cursor-active status for the partition, which is recorded in online reorganization records in the RECON data sets. A listing of the partition's database record in the RECON data sets shows OLREORG CURSOR ACTIVE=YES. A listing of the partition also shows that both sets of DBDSs are active: the first set of DBDSs listed is for the input data set and the second set of DBDSs is for the output data set, for example, DBDS ACTIVE=A-J and M-V. While the partition is in the cursor-active status, both sets of data sets must be available for the partition to be processed by any application.

The following example shows part of a listing of the RECON data sets for a HALDB partition that has the cursor-active status.

-------------------------------------------------------------------------------
04.174 12:30:54.1                   LISTING OF RECON                  PAGE 0003
-------------------------------------------------------------------------------
 DB
  DBD=POHIDKA   MASTER DB=DBOHIDK5  IRLMID=*NULL  CHANGE#=6     TYPE=PART
  USID=0000000004  AUTHORIZED USID=0000000004  HARD USID=0000000004
  RECEIVE USID=0000000004  RECEIVE NEEDED USID=0000000000
  DBRCVGRP=**NULL**
  DSN PREFIX=IMSTESTS.DBOHIDK5                          PARTITION ID=00001
  PREVIOUS PARTITION=**NULL**    NEXT PARTITION=POHIDKB
  OLRIMSID=IMS1       ACTIVE DBDS=A-J and M-V
  REORG#=00004

  FREE SPACE:
    FREE BLOCK FREQ FACTOR=2    FREE SPACE PERCENTAGE=20

  PARTITION HIGH KEY/STRING (CHAR):               (LENGTH=5  )
    K2000
  PARTITION HIGH KEY/STRING (HEX):
    D2F2F0F0F0404040404040404040404040404040404040404040404040404040

  OSAM BLOCK SIZE:
    A = 4096
    B = 4096

  FLAGS:                             COUNTERS:
    BACKOUT NEEDED        =OFF         RECOVERY NEEDED COUNT   =0
    READ ONLY             =OFF         IMAGE COPY NEEDED COUNT =0
    PROHIBIT AUTHORIZATION=OFF         AUTHORIZED SUBSYSTEMS   =1
                                       HELD AUTHORIZATION STATE=6
                                       EEQE COUNT              =0
    TRACKING SUSPENDED    =NO          RECEIVE REQUIRED COUNT  =0
    OFR REQUIRED          =NO          OLR ACTIVE HARD COUNT   =0
    PARTITION INIT NEEDED =NO          OLR INACTIVE HARD COUNT =0
    OLREORG CURSOR ACTIVE =YES    
    PARTITION DISABLED    =NO
    ONLINE REORG CAPABLE  =YES
    REORG INTENT          =NO
    QUIESCE IN PROGRESS   =NO
    QUIESCE HELD          =NO
    ALTER IN PROGRESS     =NO
    ALTER COMPLETE        =NO


  ASSOCIATED SUBSYSTEM INFORMATION:                                            
                               ENCODED  B/O NEEDED                             
     -SSID-   -ACCESS INTENT-  -STATE-   -COUNT-  -SS ROLE-                    
    IMS1         UPDATE           6         0      ACTIVE                      
-------------------------------------------------------------------------------

During the initialization phase, various error conditions, such as an unacceptable preexisting data set or an insufficient amount of disk space for an automatically created data set, can cause the initialization to fail. However, if an error occurs during or after the data set creation and validation process, but before IMS records the cursor-active status in the RECON data sets, any automatically created output data sets are retained along with any preexisting ones.

Also during the initialization phase of an online reorganization, IMS dynamically creates a program specification block (PSB) for the reorganization. The PSB name is the 7-character HALDB partition name prefixed with the single character zero ('0'). For example, a HALDB partition with the name SSN5603 has a dynamic PSB with the name 0SSN5603 for the reorganization work. This PSB does not exist in the PSBLIB or the ACBLIB, but the name can appear in a listing of RECON or in output from utilities.