Modifying the Object Size Threshold in Post Install Compare ssid0000 to use TAPE

Products

• Database Management for DB2 for z/OS - Utilities Suite
• Database Management for DB2 for z/OS - Administration Suite
• Database Management for DB2 for z/OS - Performance Suite
• Database Management for DB2 for z/OS - Recovery Suite
• Database Management for DB2 for z/OS - SQL Performance Suite
• DATABASE MANAGEMENT SOLUTIONS FOR DB2 FOR Z/OS

Issue/Introduction

Users may find that large objects (e.g., PTDB tablespaces exceeding 1500 Cylinders) are being stored on DISK by default. To optimize storage or meet specific performance requirements, these objects may need to be redirected to TAPE during the execution of the Create ssid0001 job. How to modify MODLARGE in Compare job ssid0000?

Cause

The product uses a default Object size threshold (typically 1,000,000 pages). Any object smaller than this threshold is stored on DISK, while objects exceeding it are directed to TAPE. How to modify MODLARGE in the Compare job ssid0000?

Resolution

To redirect large objects to TAPE, the threshold must be lowered by following these steps:

1. Invoke the INSMAIN utility.
2. Navigate to the INS Compare DB2 Objects panel.
3. Locate the field: Object size threshold.
4. Change the value to a lower number of pages (e.g., 500,000) depending on the size of the objects you wish to target.
   • Threshold Logic:
     • Objects > Threshold: Stored on TAPE.
     • Objects < Threshold: Stored on DISK.
5. Save the configuration and proceed with the generation of the Compare ssid0000 JCL.