PM74991: INEFFICIENT ACCESS PATH FOR RPREDICATES (RANGE OR SUBQUERY) REFERENCING A COLUMN WITH FREQUENCY, HISTOGRAM STATISTIC

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• DB2 may choose an inefficient access path for the predicates
  referencing a column with frequency, histogram statistic, and
  the predicates are range predicates or predicates with subquery(
  the subquery is not in subquery)
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: DB2 for z/OS users with queries containing   *
  *                 predicates on columns where frequency or     *
  *                 histogram statistics have been collected.    *
  ****************************************************************
  * PROBLEM DESCRIPTION: DB2 may choose an inefficient access    *
  *                      path when a user issues a query with a  *
  *                      predicate or predicates that satisfy    *
  *                      the conditions below:                   *
  *                                                              *
  *                      1. The predicate refers to a column or  *
  *                         columns where frequency or histogram *
  *                         statistics have been collected.      *
  *                      2. The predicate is a range predicate   *
  *                         with parameter marker (or parameter  *
  *                         markers) or host variable (or host   *
  *                         variables) , or the predicate refers *
  *                         to a subquery (except an EQUAL or    *
  *                         NOT EQUAL subquery).                 *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  DB2 may choose an inefficient access path for a query with a
  predicate or predicates referencing a column where frequency or
  histogram statistics have been collected.  The predicate or
  predicates are range predicates with parameter markers or host
  variables, or include subuqueries (except EQUAL or NOT
  EQUAL subqueries).
  

Problem conclusion

• The problems mentioned above are fixed so that DB2 will choose
  a more efficient access path in that situation.
  
  
  ADDITIONAL KEYWORDS:
  
  SQLACCESSPATH SQLPERFORMANCE SQLBETWEEN SQLSUBQUERY SQLPMK
  PARAMETERMARKER SQLPMARKER SQLHOSTVAR SQLLT SQLGT
  

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:

  UK90518

Modules/Macros

• DSNXODFB DSNXODFR DSNXODFT
  

Fix information

• Fixed component name

  DB2 OS/390 & Z/

• Fixed component ID

  5740XYR00

Applicable component levels

• RA10 PSY UK90518

     UP13/01/04 P F301

Fix is available

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