How to look for access path change using Plan Analyzer without rebind

Products

• Plan Analyzer for DB2 for z/OS

Issue/Introduction

Does Plan Analyzer for Db2 for z/OS (PPA) have the ability to look at the existing packages and determine changes to access path (good or bad) without actually doing the rebind?

Resolution

Yes, Plan analyzer does that with the FUTURE EXPLAIN which shows you the impact of rebinding a plan package. A Future Explain executes a dynamic EXPLAIN
command and then uses information from the Db2 Optimizer, catalog statistics, and Plan Analyzer Expert System Rules. The Future Explain tells you your access paths
when you request a bind right now.

To specify that you want to do a future explain, you need the following steps:

• Select option 1) Quick Explain or 2) EXPLAIN Strategy Services to create a Strategy.
  
  
• Type E besides your strategy if you selected option 2 to explain it.
  
  
• Turn the Update Explain Options ===> Y in the PPA Explain Strategy - Version Info.
  
  
• Set Explain Type ===> F in PPA Explain Strategy - Explain Options to indicate you want Future Explain.