BigQuery User-Defined Functions (UDFs)

BigQuery User-Defined Functions (UDFs) extend GoogleSQL with custom logic written in SQL, JavaScript, managed Python (python-3.11), or hosted externally as Remote Functions on Cloud Run and Cloud Run functions.

Usage Attribution

MUST READ: Before executing any gcloud, REST API, or MCP command, you MUST read and follow the instructions in Usage Attribution.

Choosing the Right UDF Type

Always select the lightest-weight runtime that satisfies the requirement, because BigQuery optimizes native SQL expressions inline while external runtimes incur serialization and container startup overhead: