A fix is available
APAR status
Closed as program error.
Error description
DB2 may calculate a incorrect filter factor for using BETWEEN and RANGE predicates, when a volatile table is defined as partitioned with one limit key.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: * * All users of DB2 11 for z/OS who have * * queries that include more than one range * * predicate on the same column of a volatile * * table * **************************************************************** * PROBLEM DESCRIPTION: * * DB2 can underestimate the compound * * filter factor of two range predicates * * on the same column of a volatile table * **************************************************************** * RECOMMENDATION: * **************************************************************** If a volatile table has more than one local range predicate on the same column, and one range filter factor is calculated by one method while the other range filter factor is calculated by a different method, DB2 could underestimate the compound filter factor of the two range predicates if the sum of the two range filter factors is less than 1. Example SQL: SELECT * FROM T1 WHERE T1.C1 > 0 AND T1.C1 < ?; If table T1 is a volatile table, and the sum of the filter factors for the two range predicates is less than 1, DB2 11 will get 1/tablecard as the compound filter factor of the two range predicates. Additional Keywords: SQLPERFORMANCE SQLACCESSPATH FILTERFACTOR SQLRANGE
Problem conclusion
Code is updated to get a more reasonable compound filter factor for the problem above.
Temporary fix
Comments
APAR Information
APAR number
PI72800
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
C10
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2016-11-25
Closed date
2016-12-28
Last modified date
2017-02-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI43588
Modules/Macros
DSNXOCCF
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
RC10 PSY UI43588
UP17/01/13 P F701
Fix is available
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Document Information
Modified date:
01 February 2017