A fix is available
APAR status
Closed as program error.
Error description
SQL statements may incur dynamic statement cache ( DSC ) misses when a table that is referenced in the query is using a "temporal construct". (The "temporal construct" can be related a table that uses system time (SYSTEM_TIME), business time (BUSINESS_TIME), or uses archive tables (ENABLE ARCHIVE)). As a result the statement has to go through full prepare each time it is executed and a new copy of the stmt is inserted into the DSC (resulting in multiple copies of the SQL stmt with the same characteristics in the DSC). The SQL itself does not need to have a clause with a temporal construct for the problem to occur.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All DB2 11 for z/OS users of temporal * * tables in combination with the Dynamic * * Statement Cache (CACHEDYN=YES). * **************************************************************** * PROBLEM DESCRIPTION: Users may experience high CPU * * utilization attributed to * * long prepares and duplicate * * statements in the Dynamic * * Statement Cache which increase * * the EDM pool storage used. * **************************************************************** * RECOMMENDATION: * **************************************************************** Dynamic Statement Cache matching criteria was incorrect resulting in no cache match for statements that: 1. Reference a Business Time Temporal table; and do not have the BUSTIMESENSITIVE bind option specified on the package; and do not have the CURRENT TEMPORAL BUSINESS_TIME special register value set; Or 2. Reference a System Time Temporal table; and do not have the SYSTIMESENSITIVE bind option specified on the package; and do not have the CURRENT TEMPORAL SYSTEM_TIME special register value set; Or 3. Reference an archive enabled table; and do not have the ARCHIVESENSITIVE bind option specified on the package; and have the SYSIBMADM.GET_ARCHIVE global variable set to 'N'; This causes those statements to incorrectly not match a copy in the dynamic statement cache and go through full prepares and insert a new copy into the Dynamic Statement Cache.
Problem conclusion
Dynamic Statement Cache matching criteria is modified so statements that: 1. Reference a Business Time Temporal table; and do not have the BUSTIMESENSITIVE bind option specified on the package; and do not have the CURRENT TEMPORAL BUSINESS_TIME special register value set; Or 2. Reference a System Time Temporal table; and do not have the SYSTIMESENSITIVE bind option specified on the package; and do not have the CURRENT TEMPORAL SYSTEM_TIME special register value set; Or 3. Reference an archive enabled table; and do not have the ARCHIVESENSITIVE bind option specified on the package; and have the SYSIBMADM.GET_ARCHIVE global variable set to 'N'; will now match a correct copy if it exists in the Dynamic Statement Cache. Additional Keywords: SQLDYNSTMTCACHE SQLAPTT SQLBITEMPORAL SQLSPTT
Temporary fix
Comments
APAR Information
APAR number
PI48283
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
B10
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2015-09-07
Closed date
2015-12-04
Last modified date
2016-01-21
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI33566
Modules/Macros
DSNGEPIS DSNGEPLC
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
RB10 PSY UI33566
UP15/12/22 P F512
Fix is available
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Document Information
Modified date:
21 January 2016