# Computing suspect pairs and writing a sample in Talend Data Stewardship

This scenario applies only to subscription-based Talend Platform products with Big Data and Talend Data Fabric.

Finding duplicate records is hard and time consuming especially when you are dealing with huge volume of data. In this example, tMatchPairing uses a blocking key to compute the pairs of suspect duplicates in a long list of early childhood education centers in Chicago coming from ten different sources.

It also computes a sample of the suspect duplicates and writes it in the form of tasks into a Grouping campaign in Talend Data Stewardship. Authorized data stewards can then intervene on the data sample and decide if suspect pairs are duplicates.

You can then use the labeled sample to compute a matching model and apply it on all suspect duplicates in the context of machine learning on Spark.

To replicate the example described below, download the [tmatchpairing_load_suspect_pairs_in_tds.zip](https://help.qlik.com/talend/en-US/data-matching/8.0/Content/Resources/attachments/tmatchpairing_load_suspect_pairs_in_tds.zip) file.

Before setting up the Job, make sure:

* You have been assigned in Talend Administration Center the Campaign Owner role which grants you access to the campaigns on the server.

* You have created the Grouping campaign in Talend Data Stewardship and defined the schema which corresponds to the structure of the education centers file.

### In this section

* [Creating the Job](https://help.qlik.com/talend/en-US/data-matching/8.0/computing-suspect-pairs-writing-sample-in-stewardship-creating-job)
* [Selecting the Spark mode](https://help.qlik.com/talend/en-US/data-matching/8.0/selecting-spark-mode-spark-batch?id=102)
* [Configuring the connection to the file system to be used by Spark](https://help.qlik.com/talend/en-US/data-matching/8.0/configuring-connection-to-file-system-to-be-used-by-spark?id=103)
* [Reading data and sending the fields to the next component](https://help.qlik.com/talend/en-US/data-matching/8.0/reading-data-and-sending-fields-to-next-component)
* [Computing suspect pairs and writing a sample in a Grouping campaign](https://help.qlik.com/talend/en-US/data-matching/8.0/computing-suspect-pairs-writing-sample-in-grouping-campaign)
* [Configuring the output components to write suspect pairs, unique rows and exact duplicates](https://help.qlik.com/talend/en-US/data-matching/8.0/configuring-output-components-to-write-suspect-pairs-unique-rows-exact-duplicates)
* [Executing the Job to write tasks into the Grouping campaign](https://help.qlik.com/talend/en-US/data-matching/8.0/executing-job-to-write-tasks-into-grouping-campaign)