Previewing data - 6.3

Talend Data Fabric Studio User Guide

English (United States)
Talend Data Fabric
Talend Studio
Data Quality and Preparation
Design and Development


This feature is not available for a MapReduce Job.

Like the Traces Debug mode of the Run view that allows you to monitor data processing during Job execution, the tMap component offers you that same functionality in its editor. This allows you to monitor the data mapping and processing before the execution while configuring the tMap component.

For further information about monitoring data processes from the Run view, see Row by row monitoring.

To preview data mapping and processing during tMap configuration:

  1. Activate the Traces Debug mode in the Run view. For more information regarding the Traces Debug execution mode and how to activate it, see How to run a Job in Traces Debug mode.

  2. Double-click tMap on the design workspace to open its editor.

    A new Preview column displays in the main input table and in the output tables showing a preview of the data processed, and a new tool bar displays on the top left hand corner of the Map Editor.

To monitor data processing row by row or at a certain breakpoint, simply:

Click the Previous Row button to display the data preview of the previous row, within a limit of five rows back.

Click the Next Row button to display the data preview of the next row.

Click the Next Breakpoint button to display the data preview of the next breakpoint.


To monitor your data processing at a breakpoint you first need to define one on the relevant link. To do so, right-click the relevant link on the design workspace, select Show Breakpoint Setup on the popup menu and select the Activate conditional breakpoint check box and set the Conditions in the table. A pause icon displays below the link when you access the Traces Debug mode.

Click the Kill button to stop the data processing.

To deactivate the data preview in the Map Editor:

  1. Click OK to close the Map Editor.

  2. Go back to the Run view and click the Basic Run tab.

  3. Double-click tMap on the design workspace to open the Map Editor.