You can use pushdown optimization to push transformation logic to source databases or target databases. Use pushdown optimization when you use database resources to improve the performance of the task. When you run a task configured for pushdown optimization, the task converts the transformation logic to an SQL query. The task sends the query to the database, and the database executes the query.
This article explains how to use pushdown optimization for the ODBC connection type that uses Google BigQuery ODBC drivers for mappings. This article also explains the supported pushdown optimization functions, transformations, operators, and data types.