Developers Guide

May 8, 2026 · View on GitHub

This guide contains information for developers.

Running Integration Tests

Some integration tests require access to an Azure Blob Storage account. For local test runs against Azure, create a file named abs-cs.json in the project root. Despite the file extension, the file must contain only the plain Azure Storage connection string, not a JSON object.

To get the connection string from the Azure portal:

  1. Open the storage account.
  2. In the resource menu, select Security + networking → Access keys.
  3. Select Show keys.
  4. Copy one of the Connection string values.
  5. Paste the copied value into abs-cs.json.

The file content should look like this:

DefaultEndpointsProtocol=https;AccountName=<account-name>;AccountKey=<account-key>;EndpointSuffix=core.windows.net

Use a regular Blob Storage account without Data Lake Gen2 / hierarchical namespace enabled.

Running Regression Test

This project contains some regression tests to monitor the performance cross releases. To run them locally use:

mvn verify -PregressionTests

However, a local run won't give you reliable numbers, since it's dependent on your local hardware configuration.

Getting Debug Output

In order to get the log output from inside the database set the system propertytest.udf-logs=true (by adding it with -D as jvm option in your IDE's test config) and check the files in target/udf-logs/.

Debugging & Profiling

You can use a remote debugger and profiler for this project's integration tests. To do so, use the system properties from UDF debugging Java.

When you enable debugging or profiling, this project's test will set the UDF concurrency to 1. Debugging concurrent UDFs is currently not possible due to reverse connection.