You need to migrate Teradata historical data to BigQuery with minimal programming and without relying on limited local Teradata storage. Which method is most efficient?

The BigQuery Data Transfer Service with a JDBC driver using a FastExport connection is the most efficient method because it offers a managed, serverless solution for migrating data directly from Teradata to BigQuery with minimal programming. FastExport is designed for high-speed data extraction from Teradata. Generating a TPT export script and using the bq CLI requires manual orchestration and management of the export and import processes, which is less efficient and more prone to errors than a managed service. Using BigQuery Data Transfer Service with the Teradata TPT tbuild utility is not a standard integration; tbuild is for Teradata-internal operations, not direct BigQuery integration. Exporting data via scripts, uploading to Cloud Storage, and then transferring to BigQuery adds multiple manual steps and introduces additional latency and management overhead compared to a direct transfer service.