The Secure Agent generates and executes a SELECT statement for each source that has transformation logic pushed down. Then, it reads the results of this SQL query and processes the remaining transformations in the mapping.

You can configure a mapping to use source

SQL ELT optimization

if the source and target reside in different databases.

For example, if a mapping contains a Teradata source and an Oracle target, you can configure source

SQL ELT optimization

to push some transformation logic for processing to the Teradata source.