IC73249: Joining to a VALUES clause may result in suboptimal plans.

DB2 Version 9.7 Fix Pack 5 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 6 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 7 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 9a for Linux, UNIX, and Windows
DB2 Version 9.7 Fix Pack 10 for Linux, UNIX, and Windows

APAR status

• Closed as program error.

Error description

• Using a JOIN between a VALUES clause and a table or sub-select
  might result in suboptimal query plans. If the VALUES clause
  contains multiple columns, the optimizer might not choose the
  best join method for satisfying the JOIN if the VALUES clause
  joins to multiple tables with a common local equality predicate
  as in the following example:
  
  
  SELECT ... FROM table(values(?,?),(?,?),(?,?),(?,?)) as a(a1,
  a2), b, c, d WHERE a.a1=b.b1 and a.a2=b.b2 and a.a1=c.c1 and
  a.a2=c.c2 and  a.a1=d.d1 and a.a2=d.d2 and a.a3 = ? and
  b.b3=a.a3 and c.c3=a.a3
  

Local fix

• Use an IN predicate instead of a JOIN to a VALUES clause
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All DB2 users                                                *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * Using a JOIN between a VALUES clause and a table or          *
  * sub-select  might result in suboptimal query plans.          *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to DB2 9.7 Fix pack 5 or later                       *
  ****************************************************************
  

Problem conclusion

• Upgrade to a Fix Pack containing the Fix
  

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

  DB2 FOR LUW

• Fixed component ID

  DB2FORLUW

Applicable component levels

• R970 PSN

     UP