A fix is available
APAR status
Closed as new function.
Error description
New function for DB2 V10. (dm1761)
Local fix
n/a
Problem summary
**************************************************************** * USERS AFFECTED: DB2 users that need to evaluate the * * CPU and elapsed time spent in DB2 for SQL * * that would be eligible for acceleration. * **************************************************************** * PROBLEM DESCRIPTION: This APAR allows a subsystem to model * * the existence of an accelerator to * * evaluate the CPU and elapsed time * * spent in DB2 for SQL that would be * * eligible for acceleration. * **************************************************************** * RECOMMENDATION: * **************************************************************** A new zparm and three new accounting fields have been added to provide an accelerator modeling function. Accelerator modeling allows queries to provide the CPU time and elapsed time spent processing SQL in DB2 that may be eligible for execution on an accelerator. Additionally, EXPLAIN will populate DSN_QUERYINFO_TABLE, which shows if a query is eligible for offload or not. The ACCELMODEL subsystem parameter determines whether to enable modeling of query workload for evaluating potential savings for both the accumulated elapsed time and CPU time if the plan is executed on an accelerator. Only queries that are deemed eligible for execution on an accelerator by DB2 will be included in accelerator-related fields of accounting trace IFCID 3. NO Specifies that no modeling is to be performed. This is the default setting. YES Specifies that modeling is to be performed and consider acceleration eligibility for an SQL statement and update the new accounting fields accordingly To enable modeling, the IDAA special register CURRENT QUERY ACCELERATION and zparm QUERY_ACCELERATION (set by the CURRENT QUERY ACCEL field of this panel) must be set to NONE for accelerator modeling to be used. All other values for the special register and zparm will cause DB2 to attempt to accelerate queries instead of performing accelerator modeling. This means that existing queries that already execute on the accelerator with CURRENT QUERY ACCELERATION = ENABLE, ENABLE WITH FAILBACK, ELIGIBLE, or ALL will not be part of the accelerator-related accounting fields. DB2 does not perform accelerator modeling for SQL queries executed under a native stored procedure (aka SQLPL procedure). However, DB2 does perform accelerator modeling for SQL queries executed under an external stored procedure. Accelerator modeling for native or SQLPL procedures is a consideration for the future. EXPLAIN for a statement that goes through accelerator modeling will have the following output: (1) If the query is eligible for offload, DSN_STATEMNT_TABLE.REASON = 'ACCELMODEL ELIGIBLE' (2) If the query is not eligible for offload, DSN_STATEMNT_TABLE.REASON = 'ACCELMODEL NOT ELIGIBLE' (3) DSN_QUERYINFO_TABLE will show the accelerated or not accelerated output (same as today). Column QINAME1 will have a value of 'ACCELMDL', which is normally the accelerator name (4) PLAN_TABLE and all other explain tables will show the DB2 access path Three new accounting fields will be added to the QWAC of the IFCID 3. These values do not include times from SQL executed in a native SQL stored procedure that are eligible for execution on an accelerator. QWAC_ACCEL_ELIG_ELA CL8 The accumulated elapsed time spent processing SQL in DB2 that may be eligible for execution on an accelerator. QWAC_ACCEL_ELIG_CP CL8 The accumulated CPU time spent processing SQL in DB2 that may be eligible for execution on an accelerator. QWAC_ACCEL_ELIG_SE DS CL8 The accumulated CPU time consumed on an IBM specialty engine while processing SQL in DB2 that may be eligible for execution on an accelerator. Field QWP4ACMO is added to the IFCID 106 trace record to track the ACCELMODEL parameter. Keywords: IDAAV4R1/K IDAAV3R1/K IDAAV2R1/K SQLACCELMODEL
Problem conclusion
Temporary fix
Comments
APAR Information
APAR number
PM90886
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
A10
Status
CLOSED UR1
PE
NoPE
HIPER
NoHIPER
Special Attention
YesSpecatt / New Function
Submitted date
2013-06-11
Closed date
2013-09-19
Last modified date
2013-11-04
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK97693
Modules/Macros
DSN@XAZP DSNB1TAD DSNDQWAC DSNDQWPZ DSNDSPRM DSNRUB01 DSNTIDXA DSNTIDXB DSNTIJUZ DSNTINST DSNTLRAC DSNTXAZP DSNTXSTB DSNWAACT DSNWACDC DSNWACDF DSNWDFIF DSNWVAPR DSNWVSMT DSNWVSR1 DSNWVZCK DSNWVZIT DSNWVZPS DSNWVZSA DSNWVZSS DSNWZIFA DSNXECT DSNXEDP DSNXEDS1 DSNXEET DSNXEPM DSNXERT DSNXERT2 DSNXESTR DSNXESTS DSNXODML DSNXOD4 DSNXOD5 DSNXOIN DSNXOMPS DSNXONZO DSNXOOP DSNXRCUF DSNXRRTN DSNXTAD DSNX8SMF DSNX9WCA DSNZCMD1 DSNZINIT DSN3EOT0 DSN6SPRM
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
RA10 PSY UK97693
UP13/10/04 P F310
Fix is available
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Document Information
Modified date:
04 November 2013