IC92314: QUERY EXECUTES WITH GOOD PERFORMANCE WITH IDS 10 BUT 11.70 REQUIRES OPTIMIZER DIRECTIVES TO GET BETTER PERFORMANCE

APAR status

• Closed as program error.

Error description

• Running a query with version 10.00 of IDS provides good
  performance.  After upgrading to IDS 11.70.xC5, the performance
  is not acceptable.
  
  The default plan generated by the optimizer in 11.70 is not able
  to meet the appropriate performance requirements.  Optimizer
  directives allow path of 10.00 plan to be generated.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of 11.70.xC1 through 11.70.xC8.                        *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * A complex query with many tables and joins among different   *
  * tables may experience performance issues when columns of     *
  * different tables fall into the same "equivalence class",     *
  * e.g., t1.c1 = t2. c2 and t2.c2 = t3.c3 and t3.c3 = t4.c4,    *
  * etc.                                                         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Update to IDS-11.70.xC9                                      *
  ****************************************************************
  

Problem conclusion

• Problem Fixed In IDS-11.70.xC9
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  INFORMIX SERVER

• Fixed component ID

  5725A3900

Applicable component levels

• RB70 PSN

     UP