On This Page
The data received from the Source system might, at times, not be suitable to be replicated to the Destination database or data warehouse as is. Using Transformations in Hevo, you can prepare the data in multiple ways before loading it to the Destination. Read Data Transformation to know more about scenarios where you may need to transform your data.
Note: For any Transformation that is applied on an Event, a maximum of 10,000 child Events can be generated.
Writing the Transformation
You can design and apply transformations on Events and Event Types in two ways:
To change the transformation method, click the icon in the Transformation canvas.
Note: You cannot use both methods in the same transformation. Also, transformation of one type cannot be converted to the other automatically. If you switch from one method to the other, you need to rewrite the transformation completely.
Testing the Transformation
Once you write or modify your transformations, you can test these against real sample Events received by Hevo from your Source.
To view a sample Event:
Click the Select Event Type drop-down and select the Source Event Type on which you want to test the transformation.
Click GET SAMPLE to fetch an Event from the Event Type. This is just a sample Event for testing. No changes are applied till you DEPLOY the transformation.
Click TEST to test the transformation and view the results.
You can also test the transformation on a random sample Event not specific to any Event Type. You can even modify the sample Events to test the transformation for any edge case scenario.
Testing Transformations on failed Events
You can test any transformation you have written to resolve failed Events directly within the Transformation page.
To do this:
Click the Select Event Type drop-down.
Enable the Events not Loaded option to view only the Event Types with failed Events.
Select the required Event Type and click GET SAMPLE.
Deploying the Transformation
Once you have tested the transformation, click DEPLOY. The transformation is applied to all applicable incoming Events.
You can click RESET to return to the last deployed stage.
We would advise you to monitor the Failed Events for any failures due to the newly deployed code.
Transformation Version History
Click the icon to view the history of all deployed transformations.
You can restore any past deployed transformation by selecting it and clicking RESTORE THIS VERSION. The version is restored in Draft state. You must click DEPLOY to finally deploy it.
It is advised that you test the restored transformation before you deploy it. The system warns you if you try to directly deploy it.
- Articles in this section
- Python Code-Based Transformations
- Drag and Drop Transformations
- Effect of Transformations on the Destination Table Structure
- Transformation Reference
Refer to the following table for the list of key updates made to this page:
|Date||Release||Description of Change|
|Apr-25-2022||NA||Updates the screenshots to reflect the latest UI.|
|Sep-20-2021||NA||Added a note in the overview section about the maximum number of child Events that can be created from an Event using a Transformation.|
|Mar-23-2021||1.59||- Added the section Testing Transformations on Failed Events.
- Added the bullet point Successful ingestion of Failed Events in the page overview
|Jan-24-2022||1.80||Updated the screen shots related to the Python version.|