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** Troubleshooting ** Slow performance when using DB2, relating to database maintenance and optimisations (for example re-indexing)

Troubleshooting


Problem

Customer is experiencing slow performance with Controller.
What can the customer do to improve performance, relating to DB2 database maintenance and optimisation?

Symptom

Slow performance in Controller.

Cause

There are many possible causes for slow performance with Controller.
  • TIP: For many generic examples, see separate IBM Technote #1690080.
This Technote specifically relates the scenario where all of the following are true:
  • Database hosted on DB2
  • Performance problems are directly related to poor database maintenance (typically, out of date indexes).
 
In this scenario, there are several possible causes:
  • Cause #1 - Superuser has not recently run an 'internal' database optimise, where they ticked the box 'Analyze Schema'
    • By ticking 'Analyze Schema' the DB2 database indexes/statistics get updated/improved, leading to improved performance
    • For more details, see separate IBM Technote #1367485.
  • Cause #2 - I.T. department do not have a regular/scheduled 'external' database maintenance plan (enabled on their DB2 server)
    • This would perform many of the tasks (done inside an 'internal' database optimise) automatically. Specifically, it ensures that the database indexes/statistics get updated.
    • For more details, see separate IBM Technote #1981728.
  • Cause #3 - Limitation of Controller 10.4.0 (and earlier) where the 'internal' database optimise does not update all the indexes fully
    • For more details, see separate IBM Technote #0879753.

Environment

The Controller database is hosted on DB2.

Resolving The Problem

Cause #1
Perform an internal database, and make sure you tick 'Analyze Schema'.
  • Typically this should be done 1-2 times per month.
  • For more details, see separate IBM Technote #1367485.
    
Cause #2
Ask your I.T. department to create a regular/automatic DB2 database plan.
  • For more details, see separate IBM Technote #1981728.
   
Cause #3
Either:
  • Upgrade to a later version of Controller which correctly performs the extra/enhanced re-indexing (as part of its 'internal' database optimise routine)
  • or workaround the problem by manually running the extra/enhanced re-indexing (periodically).
For more details, see separate IBM Technote #0879753

Document Location

Worldwide

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Document Information

Modified date:
03 April 2019

UID

ibm10879725

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