Database monitor view 3006 - Access Plan Rebuilt

 

Create View QQQ3006 as 
  (SELECT QQRID as Row_ID, 
          QQTIME as Time_Created, 
          QQJFLD as Join_Column, 
          QQRDBN as Relational_Database_Name, 
          QQSYS as System_Name, 
          QQJOB as Job_Name, 
          QQUSER as Job_User, 
          QQJNUM as Job_Number, 
          QQI9 as Thread_ID, 
          QQUCNT as Unique_Count, 
          QQUDEF as User_Defined,  
          QQQDTN as Unique_SubSelect_Number, 
          QQQDTL as SubSelect_Nested_Level, 
          QQMATN as Materialized_View_Subselect_Number, 
          QQMATL as Materialized_View_Nested_Level, 
          QVP15E as Materialized_View_Union_Level, 
          QVP15A as Decomposed_Subselect_Number, 
          QVP15B as Total_Number_Decomposed_SubSelects, 
          QVP15C as Decomposed_SubSelect_Reason_Code,
          QVP15D as Starting_Decomposed_SubSelect,
          QQRCOD as Reason_Code, 
          QQC21 as SubCode, 
          QVRCNT as Unique_Refresh_Counter, 
          QQTIM1 as Last_Access_Plan_Rebuild_Timestamp, 
          QQC11 as Reoptimization_Done, 
          QVC22 as Previous_Reason_Code, 
          QVC23 as Previous_SubCode,
   FROM   UserLib/DBMONTable    WHERE  QQRID=3006)

Table 1. QQQ3006 - Access Plan Rebuilt
View Column Name Table Column Name Description
Row_ID QQRID Row identification
Time_Created QQTIME Time row was created
Join_Column QQJFLD Join column (unique per job)
Relational_Database_Name QQRDBN Relational database name
System_Name QQSYS System name
Job_Name QQJOB Job name
Job_User QQUSER Job user
Job_Number QQJNUM Job number
Thread_ID QQI9 Thread identifier
Unique_Count QQUCNT Unique count (unique per query)
User_Defined QQUDEF User defined column
Unique_SubSelect_Number QQQDTN Unique subselect number
SubSelect_Nested_Level QQQDTL Subselect nested level
Materialized_View_Subselect_Number QQMATN Materialized view subselect number
Materialized_View_Nested_Level QQMATL Materialized view nested level
Materialized_View_Union_Level QVP15E Materialized view union level
Decomposed_Subselect_Number QVP15A Decomposed query subselect number, unique across all decomposed subselects
Total_Number_Decomposed_SubSelects QVP15B Total number of decomposed subselects
Decomposed_SubSelect_Reason_Code QVP15C Decomposed query subselect reason code
Starting_Decomposed_SubSelect QVP15D Decomposed query subselect number for the first decomposed subselect
Reason_Code QQRCOD Reason code why access plan was rebuilt

  • A1 - A table or member is not the same object as the one referenced when the access plan was last built. Some reasons they might be different are:

    • Object was deleted and recreated.

    • Object was saved and restored.

    • Library list was changed.

    • Object was renamed.

    • Object was moved.

    • Object was overridden to a different object.

    • This is the first run of this query after the object containing the query has been restored.

  • A2 - Access plan was built to use a reusable Open Data Path (ODP) and the optimizer chose to use a non-reusable ODP for this call.

  • A3 - Access plan was built to use a non-reusable Open Data Path (ODP) and the optimizer chose to use a reusable ODP for this call.

  • A4 - The number of rows in the table has changed by more than 10% since the access plan was last built.

  • A5 - A new index exists over one of the tables in the query

  • A6 - An index that was used for this access plan no longer exists or is no longer valid.

  • A7 - i5/OS® Query requires the access plan to be rebuilt because of system programming changes.

  • A8 - The CCSID of the current job is different than the CCSID of the job that last created the access plan.

  • A9 - The value of one or more of the following is different for the current job than it was for the job that last created this access plan:

    • date format

    • date separator

    • time format

    • time separator.
Reason_Code (continued) QQRCOD

  • AA - The sort sequence table specified is different than the sort sequence table that was used when this access plan was created.

  • AB - Storage pool changed or DEGREE parameter of CHGQRYA command changed.

  • AC - The system feature DB2® multisystem has been installed or removed.

  • AD - The value of the degree query attribute has changed.

  • AE - A view is either being opened by a high level language or a view is being materialized.

  • AF - A sequence object or user-defined type or function is not the same object as the one referred to in the access plan; or, the SQL path used to generate the access plan is different than the current SQL path.

  • B0 - The options specified have changed as a result of the query options file.

  • B1 - The access plan was generated with a commitment control level that is different in the current job.

  • B2 - The access plan was generated with a static cursor answer set size that is different than the previous access plan.

  • B3 - The query was reoptimized because this is the first run of the query after a prepare. That is, it is the first run with real actual parameter marker values.

  • B4 - The query was reoptimized because referential or check constraints have changed.

  • B5 - The query was reoptimized because MQTs have changed.
SubCode QQC21 If the access plan rebuild reason code was A7 this two-byte hex value identifies which specific reason for A7 forced a rebuild.
Unique_Refresh_Counter QVRCNT Unique refresh counter
Last_Access_Plan_Rebuild_Timestamp QQTIM1 Timestamp of last access plan rebuild
Reoptimization_Done QQC11 Required optimization for this plan.

  • Y - Yes, plan was really optimized.

  • N - No, the plan was not reoptimized because of the QAQQINI option for the REOPTIMIZE_ACCESS_PLAN parameter value
Previous_Reason_Code QVC22 Previous reason code
Previous_SubCode QVC23 Previous reason subcode

 

Parent topic:

Optional database monitor SQL view format