Unity Catalog Functions

You can register functions in Unity Catalog schemas.

Persisting functions is good for reusing code and applying permissions or filters.

The following diagram shows an example of a Unity Catalog instance with two functions: sum and my_function:

Display functions

Let's list the functions.

bin/uc function list --catalog unity --schema default

You should see a few functions. Let's get the metadata of one of these functions.

bin/uc function get --full_name unity.default.sum

In the printed metadata, pay attention to the columns input_parameters, external_language, and routine_definition.

This seems like a simple python function that takes 3 arguments and returns the sum of them. Let's try calling this function.

Behind the scenes, the invocation of the function is achieved by calling the python script at etc/data/function/python_engine.py with the function name and arguments.

bin/uc function call --full_name unity.default.sum --input_params "1,2,3"

Voila! You have invoked a function stored in UC.

Create function

Let's try and create a new function.

bin/uc function create --full_name unity.default.my_function \
--data_type INT --input_params "a int, b int" --def "c=a*b\nreturn c"

You can test out the newly created function by invoking it.

bin/uc function call --full_name unity.default.my_function --input_params "2,9"