Defining the IMS catalog with DBRC

Use the Database Recovery Control utility (DSPURX00) to define the HALDB master database and partitions for the IMS catalog.

The following code is an example of the DBRC commands that are used to define an IMS catalog and its partitions, and the secondary index for the catalog, to DBRC:

//DEFCAT  EXEC PGM=DSPURX00   
  //STEPLIB  DD  DSN=IMS.SDFSRESL,DISP=SHR  
  //SYSPRINT DD  SYSOUT=*                   
  //IMS      DD  DSN=IMS.DBDLIB,DISP=SHR    
  //SYSIN    DD  * 
    INIT.DB   DBD(DFSCD000) TYPHALDB SHARELVL(3)        
    INIT.PART DBD(DFSCD000) PART(DFSCD01) -           
     DSNPREFX(IMSVS.IMEC.DFSCD000) -               
     BLOCKSZE(8192,8192,8192,8192) -               
     KEYSTRNG('DBD     ZZZZZZZZ') -                
     GENMAX(5)                                     
    INIT.PART DBD(DFSCD000) PART(DFSCP01) -           
     DSNPREFX(IMSVS.IMEC.DFSCD000) -               
     BLOCKSZE(8192,8192,8192,8192) -               
     KEYSTRNG('PSB     ZZZZZZZZ') -                
     GENMAX(5)                                     
   INIT.DB DBD(DFSCX000) TYPHALDB SHARELVL(3)      
   INIT.PART DBD(DFSCX000) PART(DFSCX01) -         
     DSNPREFX(IMSVS.IMEC.DFSCX000)   GENMAX(3) -   
     KEYSTRNG(X'FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF') 
   LIST.DB DBD(DFSCD000) DBDS                       
   LIST.DB DBD(DFSCX000) DBDS

The database and partition names must be coded as shown in the preceding example unless your IMS system uses a catalog alias prefix. In that case, replace DFSC with the four character alias prefix in the database and partition names for the catalog and the catalog secondary index. Alias prefixes are defined in the DFSDFxxx member of the IMS.PROCLIB data set. You can use multiple database definitions.

The root key for a catalog record is the value of the RHDRSEQ field in the HEADER segment of the catalog record. This key value is generated by the IMS catalog populate utility (DFS3PU00) or the ACB generation and catalog populate utility (DFS3UACB). The value is created by concatenating the record type and the IMS member name of the resource. The record type is eight characters long and is right-padded with blank characters. The IMS member name is always eight characters long.

For example, the following example shows the root key for a DBD record with the name ACF12000.

DBD     ACF12000

The following example shows the root key for a PSB record with the name MXG88888.

PSB     MXG88888

You can specify the key as a 16 character string, or as a 32 character hexadecimal binary representation of a 16 character string.

The root key value is also used to sort catalog records into database partitions, if your catalog database consists of more than one partition. The partition high key for the last partition in the database must be high enough to contain the highest-key record in the catalog.

If the IMS catalog has a secondary index that contains only a single partition, the DFS3PU00 and DFS3UACB utilities can allocate the data sets for the secondary index automatically. If the secondary index has more than a single partition, you must allocate the partition data sets yourself.