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Creating a Job to deduplicate data

You can generate a ready-to-use Job to deduplicate data in a specific file in the Talend Studio metadata. Using the component settings of this automatically-generated Job, you can choose to output the duplicates and the unique values in two separate files or databases.

The sequence of deduplicating data in a specific file involves the following steps:
  • Selecting the file you want to deduplicate.
  • Choosing the columns on which to run the deduplicating Job.
  • If required, defining a blocking key to partition the data to be processed. A blocking key is usually needed when there is a lot of data in the file.
  • Choosing where to write the unique and duplicated records.
  • Running the generated Job.


  1. On the menu bar, select Window > Show View.
    The Show View dialog box is displayed.
  2. Expand the Help folder and then select Cheat Sheets.
  3. Click OK to close the dialog box.
    The Cheat Sheet panel is displayed in Talend Studio.
  4. On the cheat sheet icon bar, click the drop-down arrow, and from the menu select Launch Other....
    Location of the Launch Other option from the Cheat Sheets panel.
    The Cheat Sheet Selection dialog box is displayed.
  5. Expand Talend - Cheat Sheets > Job, select Deduplicate Data and click OK to close the dialog box.
    Location of the Deduplicate Data cheat sheet from the Cheat Sheet selection dialog box.

    The corresponding page is displayed in the Cheat Sheet panel. This page guides you through the steps on how to create a ready-to-use Job on certain columns in a specific file.

    Overview of the cheat sheet in the Cheat Sheet panel.
  6. Read the introduction and then click Click to Begin.

    This expands the first step in the procedure: Select File.

  7. Read the instructions and then click Click to perform.

    The Input Type Select Dialog wizard opens to guide you through the steps of creating the Job.

  8. From the Type list field, select the file type on which you want to run the Job and click OK.
    A dialog box opens showing the database and file connections defined in Talend Studio.
  9. Select the file to cleanse from the metadata connection and click OK.

    The next step in the cheat sheet is expanded.

  10. Read the instructions on how to choose the matching fields and then click Click to perform to open the next view in the wizard.
  11. Follow the instructions and switch between the wizard and the steps in the cheat sheet page till the last step: Review and Run the Generated Job.

    The wizard configures all the components and the metadata in the repository according to the settings you defined in the wizard different views and generates the Job. Talend Studio switches to the Integration perspective to display the generated Job that should look something like the following:

    Job using the tFileInputDelimited, tGenKey, tMatchGroup, tFilterRow, and two tFileOutputDelimited components.
  12. Save the Job and press F6 to execute it.


The unique and duplicate values in the file are identified and stored in the defined output files or databases. The generated Job is stored under the Job Designs node in the Repository tree view.

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