Start of change

Database monitor view 3027 - Subquery Merge

Create View QQQ3027 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,
          QVRCNT as Unique_Refresh_Counter, 
          QVPARPF as Parallel_Prefetch, 
          QVPARPL as Parallel_PreLoad, 
          QVPARD as Parallel_Degree_Requested, 
          QVPARU as Parallel_Degree_Used, 
          QVPARRC as Parallel_Degree_Reason_Code, 
          QQEPT as Estimated_Processing_Time, 
          QVCTIM as Estimated_Cumulative_Time, 
          QQREST as Estimated_Rows_Selected, 
          QQAJN as Estimated_Join_Rows, 
          QQJNP as Join_Position, 
          QQI1 as DataSpace_Number,
          QQC21 as Join_Method, 
          QQC22 as Join_Type,
          QQC23 as Join_Operator,
          QVJFANO as Join_Fanout,  
          QVFILES as Join_Table_Count,
          QVP151 as Subselect_Number_of_Inner_Subquery,
          QVP152 as Subselect_Level_of_Inner_Subquery, 
          QVP153 as Materialized_View_Subselect_Number_of_Inner, 
          QVP154 as Materialized_View_Nested_Level_of_Inner, 
          QVP155 as Materialized_View_Union_Level_of_Inner, 
          QQC101 as Subquery_Operator,  
          QVC21 as Subquery_Type, 
          QQC11 as Has_Correlated_Columns, 
          QVC3001 as Correlated_Columns
   FROM   UserLib/DBMONTable
   WHERE  QQRID=3027) 
Table 1. QQQ3027 - Subquery Merge
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 Subselect number for outer subquery
SubSelect_Nested_Level QQQDTL Subselect level for outer subquery
Materialized_View_Subselect_Number QQMATN Materialized view subselect number for outer subquery
Materialized_View_Nested_Level QQMATL Materialized view subselect level for outer subquery
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
Unique_Refresh_Counter QVRCNT Unique refresh counter
Parallel_Prefetch QVPARPF Parallel Prefetch (Y/N)
Parallel_PreLoad QVPARPL Parallel Preload (index used)
Parallel_Degree_Requested QVPARD Parallel degree requested (index used)
Parallel_Degree_Used QVPARU Parallel degree used (index used)
Parallel_Degree_Reason_Code QVPARRC Reason parallel processing was limited (index used)
Estimated_Processing_Time QQEPT Estimated processing time, in seconds
Estimated_Cumulative_Time QVCTIM Estimated cumulative time, in seconds
Estimated_Rows_Selected QQREST Estimated rows selected
Estimated_Join_Rows QQAJN Estimated number of joined rows
Join_Position QQJNP Join position - when available
DataSpace_Number QQI6 Dataspace number
Join_Method QQC21 Join method - when available
  • NL - Nested loop
  • MF - Nested loop with selection
  • HJ - Hash join
Join_Type QQC22 Join type - when available
  • IN - Inner join
  • PO - Left partial outer join
  • EX - Exception join
Join_Operator QQC23 Join operator - when available
  • EQ - Equal
  • NE - Not equal
  • GT - Greater than
  • GE - Greater than or equal
  • LT - Less than
  • LE - Less than or equal
  • CP - Cartesian product
Join_Fanout QVJFANO Join fan out. Possible values are:
  • N - Normal join situation where fanout is allowed and each matching row of the join fanout is returned.
  • D - Distinct fanout. Join fanout is allowed however none of the join fanout rows are returned.
  • U - Unique fanout. Join fanout is not allowed. Error situation if join fanout occurs.
Join_Table_Count QVFILES Number of tables joined
Subselect_Number_of_Inner_Subquery QVP151 Subselect number for inner subquery
Subselect_Level_of_Inner_Subquery QVP152 Subselect level for inner subquery
Materialized_View_Subselect_Number _of_Inner QVP153 Materialized view subselect number for inner subquery
Materialized_View_Nested_Level_of_Inner QVP154 Materialized view subselect level for inner subquery
Materialized_View_Union_Level_of_Inner QVP155 Materialized view union level for inner subquery
Subquery_Operator QQC101 Subquery operator. Possible values are:
  • EQ - Equal
  • NE - Not Equal
  • LT - Less Than or Equal
  • LT - Less Than
  • GE - Greater Than or Equal
  • GT - Greater Than
  • IN
  • LIKE
  • EXISTS
  • NOT - Can precede IN, LIKE or EXISTS
Subquery_Type QVC21 Subquery type. Possible values are:
  • SQ - Subquery
  • SS - Scalar subselect
  • SU - Set Update
Has_Correlated_Columns QQC11 Correlated columns exist (Y/N)
Correlated_Columns QVC3001 List of correlated columns with corresponding QDT number
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