Example: dbqlstepV - Detect the Longest Running Query in a Time Frame - Teradata VantageCloud Lake

Lake - Monitor Resources and Performance

Deployment
VantageCloud
Edition
Lake
Product
Teradata VantageCloud Lake
Release Number
Published
February 2025
ft:locale
en-US
ft:lastEdition
2025-11-21
dita:mapPath
wyu1683671641248.ditamap
dita:ditavalPath
pny1626732985837.ditaval
dita:id
wyu1683671641248
This example detects the longest running query in a particular time frame.
  1. Run the following command to determine what queryid has the longest query:
    SELECT
    qlog.StartTime
    ,qlog.QueryId AS QueryId
    ,((FirstRespTime - StartTime HOUR(4)) (FLOAT)) * 3600. +
           ((FirstRespTime - ((FirstRespTime - StartTime HOUR(4) )) - StartTime
           SECOND(4) ) (FLOAT)) as ResponseTime
    ,qlog.NumResultRows
    ,qlog.TotalIoCount
    ,qlog.AmpCpuTime
    ,qlog.SpoolUsage
    ,qlog.ERRORCODE
    ,qlog.ErrorText
    ,qlog.Username
    ,qlog.QueryText
    FROM
    td_metric_svc.DBQLogV qlog
    where starttime between '2022-10-31 15:36:21.62' and '2022-10-31 16:07:14.88'
    order by ResponseTime Desc;
    Result: In the output, queryid 307160898229181140 has the longest running query with a response time of 262.453597. This is partial output and the output is displayed vertically for readability.
    StartTime: 2022-10-31 15:40:58
    QueryId 307160898229181140
    ResponseTime 262.453597
    NumResultRows 5
    TotalIOCount 1442598
    AMPCPUTime 251.908
    SpoolUsage 22623870976
    Errorcode 0
    ErrorText
    UserName MEDIUM_USER1
    QueryText "-- using 6 as a seed to the RNG ...
    
    StartTime: 2022-10-31 15:36:22
    QueryId 307160898229181080
    ResponseTime 260.520936
    NumResultRows 20122
    TotalIOCount 481829
    AMPCPUTime 2106.304
    SpoolUsage 16922267648
    Errorcode 0
    ErrorText
    UserName MEDIUM_USER1
    QueryText "-- using 6 as a seed to the RNG ...
    
    StartTime: 2022-10-31 15:38:29
    QueryId 307160898229181121
    ResponseTime 255.513717
    NumResultRows 19979
    TotalIOCount 469941
    AMPCPUTime 2094.62
    SpoolUsage 16930865152
    Errorcode 0
    ErrorText
    UserName MEDIUM_USER1
    QueryText "SELECT
            O_ORDERPRIORITY,
            COUNT(*) ..."
    
    [ ... ]
  2. Determine what step in the query took the longest. To determine this, query the DBQLStepV table for the queryid found in the previous step (307160898229181140):
    select
    QueryID as QueryID
    ,StepLev1Num
    ,StepLev2Num
    ,StepName
    , StepStartTime
    ,((StepStopTime - StepStartTime HOUR(4)) (FLOAT)) * 3600. +
           ((StepStopTime - ((StepStopTime - StepStartTime HOUR(4) )) - StepStartTime
           SECOND(4) ) (FLOAT)) as StepResponseTime
    , 'Primary Cluster' as Component
    , EstProcTime
    , EstCPUCost
    , NumOfActiveAMPs
    , CPUTime
    , MaxAmpCPUTime
    , MinAmpCPUTime
    , CASE WHEN CPUTime < 1 OR (CPUTime / (HASHAMP()+1)) =0 THEN 0
    ELSE MaxAmpCPUTime/(CPUTime / (HASHAMP()+1)) END (DEC(8,2))
    AS CPUSKW
    , IOCount
    , MaxAmpIO
    , MinAmpIO
    , CASE WHEN CPUTime < 1 OR (IOCount / (HASHAMP()+1)) =0 THEN 0
    ELSE MaxAmpIO/(IOCount / (HASHAMP()+1)) END (DEC(8,2)) AS IOSKW
    , SpoolUsage
    , MaxAMPSpool
    , MinAMPSpool
    from
    td_metric_svc.DBQLStepV ql
    where
    queryid=307160898229181140 /* this is the queryid of interest */
    --and path_component_id like '%pog%'
    order by StepStartTime;
    
    Result: From the output we can see that StepLev1Num 9 has the longest response time. This step is performing an aggregation (SUM in the StepName column). This is partial output and the output is displayed vertically for readability.
    QueryId 307160898229181140
    StepLev1Num 1
    StepLev2Num 0
    StepName MLK
    StepStartTime 2022-10-31 15:40:58
    StepResponseTime 0.000266
    Component Primary Cluster
    EstProcTime 0
    EstCPUCost 0
    NumOfActiveAMPs 1
    CPUTime 0
    MaxAmpCPUTime 0
    MinAmpCPUTime 0
    CPUSKW 0.00
    IOCount 4
    MaxAmpIO 4
    MinAmpIO 0
    IOSKW 0.00
    SpoolUsage
    MaxAMPSpool
    MinAMPSpool
    
    QueryId 307160898229181140
    StepLev1Num 2
    StepLev2Num 0
    StepName MLK
    StepStartTime 2022-10-31 15:40:58
    StepResponseTime 0.000531
    Component Primary Cluster
    EstProcTime 0
    EstCPUCost 0
    NumOfActiveAMPs 1
    CPUTime 0
    MaxAmpCPUTime 0
    MinAmpCPUTime 0
    CPUSKW 0.00
    IOCount 4
    MaxAmpIO 4
    MinAmpIO 0
    IOSKW 0.00
    SpoolUsage
    MaxAMPSpool
    MinAMPSpool
    
    [ ... ]
    
    QueryId 307160898229181140
    StepLev1Num 9
    StepLev2Num 0
    StepName SUM
    StepStartTime 2022-10-31 15:41:03
    StepResponseTime 234.083157
    Component Primary Cluster
    EstProcTime 96.69273423
    EstCPUCost 21776.148969
    NumOfActiveAMPs 96
    CPUTime 2281.164
    MaxAmpCPUTime 36.54
    MinAmpCPUTime 14.352
    CPUSKW 0.77
    IOCount 1235766
    MaxAmpIO 18911
    MinAmpIO 8238
    IOSKW 0.73
    SpoolUsage 22623870976
    MaxAMPSpool 413634560
    MinAMPSpool149807104
    
    [ ... ]