IT43422: SELECT CHOOSING SLOWER QUERYPLAN IN 14.10. THAN IN 11.50 - RELATED TO MULTI INDEX SCAN

APAR status

• Closed as program error.

Error description

• A select is choosing a slower queryplan in 14.10
  11.50. uses multi index scan
  
    1) informix.tab1: INDEX PATH
  
      (1) Index Name: informix.ind3
          Index Keys: c1   (Serial, fragments: ALL)
          Lower Index Filter: informix.tab1.c1[1,10] = <subquery>
  
      (2) Index Name: informix.ind4
          Index Keys: c2  (Serial, fragments: ALL)
          Lower Index Filter: informix.tab1.c2[1,10] = <subquery>
  
  14.10 puts it into the filter
  
    1) informix.tab1: INDEX PATH
  
          Filters: ((tab1.c2[1,10] = <subquery> OR
  informix.tab1.c1[1,10] = <subquery> )
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of Informix Server prior to 12.10.xC16 and 14.10.xC11. *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to Informix Server 12.10.xC16 or 14.10.xC11 (when    *
  * available).                                                  *
  ****************************************************************
  

Problem conclusion

• Fixed in Informix Server 12.10.xC16 and 14.10.xC11.
  

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