Working with Transformation Scripts

These topics describe the process of creating and applying transformation scripts, using the custom transform functions.

Transformation script workflow
At a high level, writing a transformation script and applying it to your data involves the following steps:
Writing transformations
You can write transformations in the Transform area of Studio, using the Transformation Editor. Transformations can contain attributes and records from your project data set as variables, and can create new attributes to hold the transformed values.
Exception handling and debugging
These topics describe exception handling in Transform and show how to debug individual transformations.
Preview mode
You can preview a transformation at any time by clicking Preview, to see the effect it will have on your project data set. Preview mode is also a useful debugging tool, as it detects any runtime errors or corner case exceptions your transformation contains.
Editing, deleting and rearranging your transformations
You can edit individual transformations after you have added them to your transformation script. You can also edit the transformation script itself by rearranging and deleting transformations.
Applying transformation scripts to project data sets
You can apply your transformation script at any point to make changes in your project data set. When the script finishes running, users working with your project can view, search, use guided navigation and interact with the transformed data in Transform, Explore, and Discover areas of Studio.
Transform locking
The Transform area in Studio provides a locking mechanism to ensure that multiple users working with the same data set within a project can't transform the data set at the same time.
Creating a new Hive table with the transformation script
When you use Create a Data Set in the Transformation Editor, your transformation script is applied to the source Hive table your project data set was created from. This operation creates a new Hive table in the Dgraph index and adds a new data set to the Catalog.