tFixedFlowInput MapReduce properties (deprecated)

Schema and Edit Schema

A schema is a row description, it defines the number of fields that will be processed and passed on to the next component. The schema is either built-in or remote in the Repository.

Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

• View schema: choose this option to view the schema only.

• Change to built-in property: choose this option to change the schema to Built-in for local changes.

• Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion. If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the Repository Content window.

Built-in: The schema will be created and stored locally for this component only. Related topic: see Talend Studio User Guide.

Repository: You have already created the schema and stored it in the Repository, hence can be reused in various projects and Job designs. Related topic: see Talend Studio User Guide.

Mode

From the three options, select the mode that you want to use.

Use Single Table : Enter the data that you want to generate in the relevant value field.

Use Inline Table : Add the row(s) that you want to generate.

Use Inline Content : Enter the data that you want to generate, separated by the separators that you have already defined in the Row and Field Separator fields.

Number of rows

Enter the number of lines to be generated.

Values

Between inverted commas, enter the values corresponding to the columns you defined in the schema dialog box via the Edit schema button.

Global Variables

NB_LINE: the number of rows processed. This is an After variable and it returns an integer.

ERROR_MESSAGE: the error message generated by the component when an error occurs. This is an After variable and it returns a string. This variable functions only if the Die on error check box is cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl + Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio User Guide.

Usage rule

In a Talend Map/Reduce Job, it is used as a start component and requires a transformation component as output link. The other components used along with it must be Map/Reduce components, too. They generate native Map/Reduce code that can be executed directly in Hadoop.

Note that in this documentation, unless otherwise explicitly stated, a scenario presents only Standard Jobs, that is to say traditional Talend data integration Jobs, and non Map/Reduce Jobs.

Hadoop Connection

You need to use the Hadoop Configuration tab in the Run view to define the connection to a given Hadoop distribution for the whole Job.

This connection is effective on a per-Job basis.