LDS

• LDS is a short form of Linear DataSet and is a byte-stream dataset in traditional z/OS files.
• LDS is used mainly by IBM DB2, z/OS system but is rarely used in application programs.
• Data from LDS is accessed as byte-addressable strings in virtual storage.
• LDS has a control interval (CI) size multiple of 4096 bytes and has no control information in its CI. i.e., no RDFs and CIDFs.
• LDS is the VSAM dataset type used by DIV (Data-In-Virtual) facility.
• Logical records should be blocked and deblocked by the application program to avoid concurrent updates.
• Logical records are not visible from the VSAM point of view. i.e., LDS is a non-VSAM dataset with some VSAM features.
• Unlike the ESDS and RRDS, LDS contains a DATA component only.

DEFINE LDS Syntax -

IDCAMS DEFINE CLUSTER command with LINEAR is used to create the LDS dataset.

Syntax - JCL for creating LDS dataset with minimum parameters

//job-card
//*
//STEP01  EXEC PGM=IDCAMS
//SYSPRINT  DD SYSOUT=*
//SYSIN     DD *
    DEFINE CLUSTER (NAME(userid.CLUSTER.NAME)	–
		CYLINDERS(primary secondary)		–
       	VOL(XXXXXX) 						–
		BUFFERSPACE(buffer-space)			–
		CISZ(ci-size)						– 
		FREESPACE(primary secondary)		–
        LINEAR	 							–
        NOREUSE 							–
        OWNER(userid) ) 					–
      DATA (NAME(userid.CLUSTER.NAME.DATA))		–
		CATALOG(XXXXXX)
/*

Create LDS Example -

Scenario - Create LDS using the IDCAMS utility.

JCL -

Full Example   

----+----1----+----2----+----3----+----4----+----5----+
...
//STEP01   EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=*
//SYSOUT   DD SYSOUT=*
//SYSIN    DD  *
  DEFINE CLUSTER(NAME(MATEGJ.TEST.LDS)  - 
     CYLINDERS(2,1)       -
     CISZ(4096)           -
     VOLUMES(DEVHD4)      - 
     LINEAR               -
     REUSE     )          -
  DATA(NAME(MATEGJ.TEST.LDS.DATA))
/*
...

Output -

Once the above JCL is submitted, check the MAXCC of the job for any errors. If the MAXCC is 00 or 04, LDS is successfully created.

Delete LDS Example -

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Scenario - Delete LDS using the IDCAMS utility.

JCL -

Full Example   

----+----1----+----2----+----3----+----4----+----5----+
...
//STEP01   EXEC PGM=IDCAMS
//SYSPRINT DD   SYSOUT=*
//SYSIN    DD   *
      DELETE 'MATEGJ.TEST.LDS'
/*
...

In the above JCL, MATEGJ.TEST.LDS is the LDS name that is planned to delete.

Output -

Once the above JCL is submitted, check the MAXCC of the job for any errors. If the MAXCC is 00 or 04, LDS successfully got deleted.

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