16.10 - Syntax for Operator-level Commands - Parallel Transporter

Teradata Parallel Transporter Reference

Product
Parallel Transporter
Release Number
16.10
Published
July 2017
Content Type
Programming Reference
Publication ID
B035-2436-077K
Language
English (United States)

The following syntax is required for operator-level commands using twbcmd.



where:

Syntax Element Description
jobId jobId is the jobName followed by a “-”, then followed by the Teradata PT-generated sequence number.

jobName specifies the name of the job targeted by the command.

operatorCommandId Specifies the identity of a Stream operator copy and allows changes to the Rate value for that copy only, while the job is running. When a job step contains multiple Stream operator copies with differing rate values, Teradata PT will automatically use the lowest rate value for all instances.

Use the operatorCommandID to identify an operator copy and change the rate value.

To change the Rate value of a Stream operator copy, you must declare the operatorCommandID attribute in the Stream operator DEFINE OPERATOR statement.

Use one of the following two methods to change the Rate:

  • Assign a value such as ‘step#1’ to the OperatorCommandID attribute in the Stream operator copy that requires the Rate change (in the APPLY statement). Then use the following command:
    twbcmd <jobid> step#1 RATE=2000
  • If a value was NOT assigned for the OperatorCommandID attribute in the Stream operator copy that requires the Rate change, the system will generate a default ID composed of the operatorName and a process ID number. Process ID numbers for operators appear on the command screen when the job step that contains the operator begins to execute.

    An example of a system-generated ID would be similar to the following: my_operator_name3456

    Use the following command to identify an operator by default ID and change the rate value:

    twbcmd <jobid> my_operator_name3456 RATE=2000
rate=statementRate Option that specifies the maximum number of DML statements per minute the Stream operator can submit to the Teradata Database.

Use the twbcmd Rate option to slow down a Teradata PT job for other higher priority jobs and to speed it up again after the priority job has completed.

The statement rate can also be specified in a DEFINE OPERATOR statement, by using the Stream operator Rate attribute. When both values are present, the twbcmd rate value will supersede the Stream operator attribute Rate value.

When a job step contains multiple occurrences of the Stream operator with differing Rate values, Teradata PT will automatically use the lowest rate value for all instances.

The specified Rate value must be either:

  • a whole number greater than zero

    or,

  • unlimited
    The default statement rate, if not set using either the Stream operator Rate attribute or by twbcmd, is unlimited. Specifying ‘unlimited’ for the twbcmd Rate value means you are changing the value back to the default after having set the value in the Stream operator.

When the twbcmd Rate option is used, the Stream operator changes the statement rate to the new value and displays a message showing the new value.

If the specified rate is greater than the packing factor, the Stream operator will send the number of rows equal to the packing factor.

periodicity=periodicity Option that specifies that the DML statements sent by the Stream operator to the Teradata Database be as evenly distributed as possible over each one minute interval. periodicity sets the number of sub-intervals per minute.

For instance, if the rate is 1600 and the periodicity is 10, then the maximum number of statements submitted is 160 (1600/10) every 6 (60/10) seconds.

Valid values are between 1 and 600.

The default value is 4, that is, four 15 second intervals per minute.

If the statement rate is unlimited, then periodicity will be ignored.

The periodicity can also be specified in a DEFINE OPERATOR statement, by using the Stream operator Periodicity attribute. When both values are present, periodicity will supersede the Stream operator Periodicity attribute value.