Table of Contents

Search

  1. Preface
  2. Mappings
  3. Data catalog discovery
  4. Parameters
  5. Visio templates

Mappings

Mappings

In-out parameters

In-out parameters

An in-out parameter is a placeholder for a value that stores a counter or task stage.
Data Integration
evaluates the parameter at run time based on your configuration.
In-out parameters act as persistent task variables. The parameter values are updated during task execution. The parameter might store a date value for the last record loaded from a data warehouse or help you manage the update process for a slowly changing dimension table.
For example, you might use an in-out parameter in one of the following ways:
Update values after each task execution.
You can use the SetVariable, SetMaxVariable, SetMinVariable, or SetCountVariable function in an Expression transformation to update parameter values each time you run a task.
To view the parameter values after the task completes, open the job details from the
All Jobs
or
My Jobs
page. You can also get these values when you work in the Mapping Designer or through the REST API.
Handle incremental data loading for a data warehouse.
In this case, you set a filter condition to select records from the source that meet the load criteria. When the task runs, you include an expression to increment the load process. You might choose to define the load process based on one of the following criteria:
  • A range of records configured in an expression to capture the maximum value of the record ID to process in a session.
  • A time interval, using parameters in an expression to capture the maximum date/time values, after which the session ends. You might want to evaluate and load transactions daily.
You can use in-out parameters in the following transformations:
  • Source
  • Target
  • Aggregator (but not in expression macros)
  • Expression (but not in expression macros)
You cannot use in-out parameters in an
elastic mapping
.
For each in-out parameter you configure the variable name, datatype, default value, aggregation type, and retention policy. You can also use a parameter file that contains the value to be applied at run time. For a specific task run, you can change the value in the
mapping
task.
Unlike input parameters, an in-out parameter can change each time a task runs. The latest value of the parameter is displayed in the job details when the task completes successfully. The next time the task runs, the
mapping
task compares the in-out parameter to the saved value.
You can also reset the in-out parameters in a
mapping
task, and then view the saved values in the job details.


Updated June 29, 2020