PI57200: SQLCA.SQLERRD3 FILLED UNEXPECTED FOR IDAA CASE OF ENABLE WITH FAILBACK AND QUERY FAILS BACK

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• SQLCA.SQLERRD3 filled unexpected for IDAA case of ENABLE WITH
  FAILBACK and query fails back
  

Local fix

• n/a
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All DB2 10 and DB2 11 for z/OS users of      *
  *                 the IBM DB2 Analytics Accelerator and DB2    *
  *                 acceleration behavior ENABLE WITH FAILBACK   *
  ****************************************************************
  * PROBLEM DESCRIPTION: Incorrect value can be returned in      *
  *                      SQLERRD(3) field of SQLCA on OPEN       *
  *                      statement when a DB2 query is           *
  *                      accelerated for the IBM DB2 Analytics   *
  *                      Accelerator but DB2 executes the query  *
  *                      without acceleration due to an error    *
  *                      from the accelerator during OPEN.       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  When users request DB2 acceleration behavior ENABLE WITH
  FAILBACK for running queries on the IBM DB2 Analytics
  Accelerator and the accelerator returns an error during the
  PREPARE or first OPEN for a query, DB2 executes the query in
  DB2 without acceleration. When the accelerator returns an
  error during the first OPEN for a query, DB2 implicitly
  re-PREPAREs before executing OPEN statement for the FAILBACK
  process.
                                                               .
  SQLERRD(3) field in SQLCA returns different information for
  different statements. For PREPARE statement, it contains the
  estimated number of rows selected. For OPEN statement, it
  contains the number of rows affected by the embedded data
  change statement of a cursor for a SELECT with data change
  statement or for a SELECT INTO.
                                                              .
  In the reported case, when DB2 implicitly re-PREPAREd a query
  for the FAILBACK process after an error during OPEN for the
  query, the SQLERRD(3) value for PREPARE statement was
  incorrectly returned to OPEN request.
                                                              .
  Additional Keywords:
    IDAAV2R1/K IDAAV3R1/K IDAAV4R1/K IDAAV5R1/K
    SQLERRD 2  SQLERR(3) SQLSTORAGE DB2STGLK/K
    SQLDYNSTMTCACHE
  

Problem conclusion

• DB2 has been changed to correctly return the value for OPEN
  statement in SQLERRD(3) field to OPEN request even when the
  implicit re-PREPARE of a query is processed in DB2 for the
  FAILBACK process.
                                                              .
  This APAR also resolves a potential issue regarding the
  handling of cached dynamic statements that are processed
  after an implicit PREPARE for FAILBACK processing results
  in a negative SQLCODE. In such cases, DB2 may not decrement
  a copy counter in an internal control block which could
  eventually lead to out-of-storage in the Dynamic Statement
  Cache pool.
  

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:

  UI37519 UI37520

Modules/Macros

• DSNXERT2
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RA10 PSY UI37519

     UP16/05/19 P F605

• RB10 PSY UI37520

     UP16/05/19 P F605

Fix is available

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