Sunday, August 25, 2013

JCL Specials

Symbols used in JCL datasets
1. && - Temporary Datasets
2. & -  Symbolic parameters in procedures
3. * - Referbacks

Temp Datasets
1. Without DSN - //DATA1 DD
2. With DSN    - //DATA2 DD DSN=&&tempdata

Special Programs
1. IGYCRCTL - Compilation
2. IEWL     - Link/Edit 
3. DSNHPC   - Precompile
4. IKJEFT01 - Bind

System Programs
1. IEF* - Program produced by scheduler group
2. IEB* - Dataset utility programs
3. IEH* - System utility programs
4. IEW* - Linkage/Loading programs

Sunday, August 18, 2013

Overrides In JCL

1. REGION Parameter - JOB Over-rides EXEC

//JOB1 JOB (A123),'XYZ'
//        REGION=40K   
//STEP1 EXEC PGM=PGM1,REGION=10K
//STEP2 EXEC PGM=PGM2,REGION=20K

Example : If STEP1 utilises complete 10K,also STEP2 utilises 20K but require more region , it over-rides its step region declaration and utilises the job region declaration (Provided there is no region requirement from any other step).
But if it exceeds the JOB region declaration, the job abebds.

2.TIME Parameter - EXEC Over-rides JOB

//JOB1 JOB (A123),'XYZ'
//        TIME=12
//STEP1 EXEC PGM=PGM1,TIME=04
//STEP2 EXEC PGM=PGM2,TIME=04
//STEP3 EXEC PGM=PGM3,TIME=02

Example : If STEP1 or STEP2 utilises more than 4 minutes,then even though total time for job is 12 minutes, the steps are not executed and the job abends.
If JOB is coded smaller time than the EXEC, then the JOB will terminateto the specified time of the JOB.

3. COND Paramter - JOB Over-rides EXEC

4. JOBLIB AND STEPLIB Parameters - STEPLLIB over-rides JOBLIB