Tips and best practices for the FPA Reorg function
The FPA Reorg function supports several keywords that improve the performance of FPA Reorg jobs and that further simplify management of DEDBs.
Improving performance
- Specify the number of areas to reorganize concurrently
- When you reorganize multiple areas, use the ITASKCTL keyword to
control the number of areas to reorganize concurrently. The default
value of the ITASKCTL keyword is 4. Change the value to optimize the
run time and CPU time of the FPA Reorg job.
Increasing the value of the ITASKCTL keyword might affect the resources in the following ways:
- Reduced job run time.
- Slightly increased CPU time.
- Increased region size.
For more information, see ITASKCTL keyword.
- Specify the number of areas to analyze concurrently
- When you reorganize multiple areas, use the ATASKCTL keyword to
control the number of areas to analyze concurrently. The default
value of the ATASKCTL keyword is the value that you specify for the
ITASKCTL keyword. Change the value to optimize the run time and CPU
time of the FPA Reorg job. The ATASKCTL keyword is effective except
when PTRCHKLVL=NONE is specified.
Increasing the value of the ATASKCTL keyword might affect the resources in the following ways:
- Reduced job run time.
- Slightly increased CPU time.
- Increased region size.
For more information, see ATASKCTL keyword.
- Pre-load CIs into data space storage
- If you specify ICACHE=YES, FPA pre-loads the control intervals
(CIs) from the DEDB areas into data space storage and accesses the
CIs in data space storage instead of accessing the CIs in VSAM data
sets. Therefore, the run time of the job decreases. The pre-loaded
CIs include those IOVF and SDEP portions of the areas.
ICACHE=NO is recommended only for the following situations:
- You specify a large value for the ITASKCTL keyword. In this case, data from all concurrently processed DEDB areas is pre-loaded into data space storage concurrently, and the amount of data space that the thread tasks of FPA use might be considerable.
- No segments or only a few segments exist in the IOVF and SDEP portions. In this case, there is no advantage to pre-loading IOVF and SDEP portions into data spaces.
For more information, see ICACHE keyword.
Using the function more effectively and efficiently
- Perform syntax check
- If you specify SCAN=YES on the GLOBAL command, FPA does not run
the reorganization process but it checks the syntax of the commands,
keywords, and parameters that you specify in the JCL. Use this
option if you want to verify the syntax of HFPSYSIN control statements
when you create new JCL.
For more information, see SCAN keyword.
- Generate image copies during the job
- If you specify ICOUT=YES, after FPA reorganizes the areas, FPA
starts IMS HP Image Copy to generate
image copies of the areas. If you use this option, you do not need
to code another job step to generate image copies.
When you specify ICOUT=YES, you must specify the IMS HP Image Copy library on the STEPLIB DD statement. You can also use the ICEIN DD statement to specify the control statements for IMS HP Image Copy.
For more information, see ICOUT keyword.
- Analyze DEDB areas during the job
- If you specify PTRCHKLVL=FULL or QUICK, FPA analyzes the reorganized
areas. If you use this option, you do not need to code another job
step to analyze DEDB areas. If you also specify the REPORT subcommand,
FPA generates reports that you can use to analyze the reorganized
areas.
For more information, see PTRCHKLVL keyword.
Resolving problems
- WER039A INSUFFICIENT VIRTUAL STORAGE
- If this message was issued during the SYNCSORT process, use the xTAKCTL
keyword to reduce the number of areas to process concurrently, and specify the following DD
statement in your
JCL.
//$ORTPARM DD* VSCORE=256K,VSCORET=3M,MINCORE=256K /*
- ICE046A 0 SORT CAPACITY EXCEEDED - RECORD COUNT nnnnnnnn
-
If this message was issued during the DFSORT process, specify SORTOPT_FILSZ=AUTO so that FPA automatically estimates the number of intermediate records, calculates the value of the FILSZ parameter, and adds the FILSZ parameter to the SORT control statement. The SORTOPT_FILSZ=AUTO option helps to prevent jobs from failing due to lack of sort work space.