Query Step Information Log Table: DBQLStepTbl - Teradata Database

DBC.DBQLStepTbl Field

Description

CollectTimeStamp

Time that the rows were written to the database. This field is also part of the multi-column NUPI (see also ProcID).

For more information on CollectTimeStamp, see “Comparing CollectTimeStamp Value Between Tables” on page 380.

CPUTime

This is the CPU seconds for this step.

Note: For requests using algorithm 1, the CPUTime shown in the first parallel step represents usage for the entire set of parallel steps.

CPUTimeNorm

This is the normalized AMP CPU seconds for this step (used for co-existent systems).

Note: For requests using algorithm 1, the CPUTimeNorm shown in the first parallel step represents usage for the entire set of parallel steps.

DispatchSeq

This field is populated only for requests that use algorithm 3 of DBQL CPU/IO Collection.

Dispatch sequence, the order in which the step was handled by the dispatcher itself or dispatched to the AMPs, beginning with '1'.

EstCPUCost

An estimate of the milliseconds of CPU time for the step, as determined by the Optimizer.

EstHRCost

An estimate of other costs for the step. There is no comparable actual data for this estimate.

EstIOCost

An estimate of service time in milliseconds for I/O for this step. There is no comparable actual data for this estimate.

EstNetCost

An estimate of the BYNET service time in milliseconds for the step. There is no comparable actual data for this estimate.

EstProcTime

The estimated processing time as determined by the Optimizer.

Note: This time is reported in seconds.

EstRowCount

The estimated row count for this step.

For a Partial Redistribution and Partial Duplication (PRPD) plan split step, EstRowCount is the estimated row counts for all split spools.

Note: A split step is a RETRIEVE or JOIN step with “split into” appearing in the EXPLAIN when target spools are generated.

EstRowCountSkew

In PRPD, the estimated row count for the skew split spool (which contains the rows with skewed values of the relation in this step).

EstRowCountSkewMatch

In PRPD, the estimated row count for the skew match split spool (which contains the rows with skewed values of the other relation to be joined with the relation in this step).

ExtraField19

The persistent portion of the DBQLStepTbl.SpoolUsage column.

ExtraField23

Most significant integer part of the persistent portion of the DBQLStepTbl.SpoolUsage column.

ExtraField24

Least significant integer part of the persistent portion of the DBQLStepTbl.SpoolUsage column.

FragmentNum

Indicates the plan fragment to which the current step belongs. For a static plan, this is set to NULL.

IOCount

This is the number of logical I/Os used by this step.

Note: For requests using algorithm 1, the IOCount shown in the first parallel step represents the entire set of parallel steps.

IOKB

Logical I/Os in KB per step.

LockDelay

Maximum wait time to get a lock on an object in centiseconds. The maximum value is 32,767 centiseconds.

LSN

The Logon Sequence Number used by load utility.

MaxAmpCPUTime

CPU secondsof the highest CPU utilized AMP in the step.

MaxAmpCPUTimeNorm

Normalized maximum CPU seconds for an AMP.

Note: Normalized columns, such as MaxAmpCPUTimNorm, are for co-existence systems only.

MaxAmpIO

The highest logical I/O count on the AMP with the highest logical
I/O usage for the step.

MaxAMPSpool

If you are using DBQL CPU/IO Collection algorithm 3, MaxAMPSpool is the largest peak spool usage of any AMP for this step. For other algorithms, MaxAMPSpool is the highest spool usage on any AMP at the end of the step.

MaxCPUAmpNumber

The number of the AMP with the highest CPU usage for the step.

MaxCPUAmpNumberNorm

Number of the AMP with the maximum normalized CPU seconds for co-existence systems.

MaxIOAmpNumber

The number of the AMP with the highest logical I/O usage for the step.

MaxSpoolAmpNumber

Number of the AMP with the highest spool usage.

MinAmpCPUTime

CPU seconds of the lowest CPU utilized AMP in the step.

MinAmpCPUTimeNorm

Normalized minimum CPU seconds for an AMP.

Note: Normalized columns, such as MinAmpCPUTimeNorm, are for co-existence systems only.

MinAmpIO

Logical I/O count of the lowest logical I/O utilized AMP in the query.

MinAMPSpool

If you are using DBQL CPU/IO Collection algorithm 3, MinAMPSpool is the smallest peak spool usage of any AMP for this step. For other algorithms, MinAMPSpool is the lowest spool usage of any AMP at the end of the step.

NumCombinedPartitions

If there is static partition elimination for the step or if a noPI table or join index has column partitions, the number of combined partitions accessed (not eliminated). Otherwise, the column is null.

NumContexts

For column-partitioned tables or join indexes: the number of contexts allocated to access partitions at the same time as a source or target relation that has partitioning. Otherwise, the column is null.

NumCPReferences

For column-partitioned tables or join indexes: the number of column partitions referenced in a column-partitioned source or target. Otherwise, the column is null.

NumofActiveAMPs

The number of AMPs involved with the step.

PhysIO

Physical I/O count per step.

PhysIOKB

Physical I/Os in KB per step.

ProcID

Unique processor ID of the Dispatcher and part of the multi-column NUPI (see also CollectTimeStamp).

QueryID

Internally-generated identifier of the query.

Note: QueryID is a system-wide unique field; You can use QueryID to join DBQL tables or the DBC.TdwmExceptionLog table with DBQL tables without needing ProcID as an additional join field.

RowCount

For:

Note: If “split into” appears in the EXPLAIN of a RETRIEVE or JOIN step, Teradata Database is using PRPD.

RowCount2

For:

RowCount3

For:

Note: For the number of rows inserted by the EXE step, see RowCount. For the number of rows updated by the EXE step, see RowCount2.

RowsWComprColumns

Number of rows with compressed columns.

SpoolUsage

Spool usage varies during a step. If you are using DBQL CPU/IO Collection algorithm 3, SpoolUsage is the peak spool usage in bytes for this step. For other algorithms, SpoolUsage is the amount of spool usage for the AMP at the end of the step.

SSRReceiverCount

The number of Single-Sender Redistribution (SSR) receiver AMPs that the step uses to redistribute rows. If the step does not use SSR for row redistribution, the value is zero.

StatementNum

Statement number with which the step is associated. If associated with multiple statements (for example, array insert), this is the highest statement number associated with this step.

StepInstance

This field is populated only for requests that use algorithm 3 of DBQL CPU/IO Collection.

Step instance number for steps that are repeated. If a step is dispatched 3 times, there will be one summarized step logged for the 3 instances of the same step number and the step instance field will be 3, indicating that 3 steps instances are represented. This field will be 1 for non-repeated steps.

StepLev1Num

Step number. If this row is for a parallel step, the number is repeated for as many parallel steps as were used for this step (for examples, see StepLev2Num).

StepLev2Num

If this row is for a parallel step, this is the second-level number of the step that spawned it.

For example, if the value of StepLevl1Num is 4 and this row logs the first parallel step for step 4, this value is 1 (and would read 04 01). If this row logs the second row generated for step 4, this value is 2 (and would read 04 02), and so forth.

If this row is not a parallel-step row, this value is 0.

StepName

Abbreviation of the internal name used to identify this step (for example, DEL for a DELETE step).“RESP” is a pseudo step that may appear after the last response of a DBQL logged request, depending on the setting of the DBS Control utility field DBQLLogLastResp.

StepStartTime

Timestamp when the step was sent to the AMP to the nearest micro second.

StepStatus

This field is populated only for requests that use algorithm 3 of DBQL CPU/IO Collection.

The step status, indicating dispatcher and AMP step disposition. Values include:

StepStopTime

Timestamp when the step returned from the AMP to the nearest micro second.

StepWD

The Workload Definition in effect for the step.

TriggerKind

TriggerNestLevel

TriggerLevelKind: A composite of trigger details.

ExtraField21 = TriggerKind + 100,000 * TriggerNestingLevel. To interpret this field, see the TriggerKind and TriggerNestingLevel fields of the QryLogSteps view.

TriggerKind bit flags:

The TriggerNestingLevel can range from 0-255.

UtilityTableId

The table ID for the utility.

This field is always 0.

VHLogicalIO

VERYHOT logical I/O count per step.

VHLogicalIOKB

VERYHOT logical I/Os in KB per step.

VHPhysIO

VERYHOT physical I/O count per step (VERYHOT cylinder index and data block I/Os that were handled by physical disk I/Os.)

VHPhysIOKB

VERYHOT physical I/Os in KB per step.