PH47541: IMPROVE DB2 QUERY PERFORMANCE ON ECLIPSELINK BY ALTERING PARAMETER BINDING BEHAVIOR

APAR status

• Closed as program error.

Error description

• EclipseLink currently disables parameter binding for JPA
  queries (JPQL & Criteria) on DB2 & DB2 z/OS. EclipseLink does
  this because EclipseLink does not know when is/isn't legal for
  DB2 & DB2 z/OS to use parameter markers. Without using SQL
  parameter markers within prepared statements, there is a
  performance degradation as DB2 has prepared statement cache
  misses.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server - Java Persistence API -             *
  *                  EclipseLink                                 *
  ****************************************************************
  * PROBLEM DESCRIPTION: Add support to EclipseLink for DB2      *
  *                      and DB2 zOS SQL query parameter         *
  *                      binding                                 *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  Currently, EclipseLink disables parameter binding for queries
  that contain certain functions (ABS, SQRT, MOD, ect ), when
  running against DB2. However, usage of un-typed parameter
  markers within many of these functions is  permitted on DB2
  and DB2 zOS.
  This issue adds support to EclipseLink so that SQL functions
  that allow un-typed parameters on DB2 & DB2 zOS will use
  parameter markers; if the JPQL and/or Criteria API use
  parameters.
  This issue adds support for EclipseLink to allow partial
  binding of parameters; making the determination on when to
  bind/not to bind on an individual level and not a query level.
  

Problem conclusion

• The fix for this APAR changes the EclipseLink implementation
  and involves an update to the third-party source. See
  https://github.com/eclipse-ee4j/eclipselink/issues/1504
  
  This fix is currently targeted for WebSphere Application
  Server 9.0.5.13 and WebSphere Liberty 22.0.0.6. For more
  information, see 'Recommended Updates for
  WebSphere Application Server':
  https://www.ibm.com/support/pages/node/715553
  

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

  WEBSPHERE APP S

• Fixed component ID

  5724J0800

Applicable component levels