Early Selection Optimization with the SQL Transformation
Early Selection Optimization with the SQL Transformation
The Data Integration Service can perform early selection optimization with an SQL transformation if the filter condition references only pass-through ports and the SQL transformation does not have side effects.
The SQL transformation has side effects under the following circumstances:
The SQL query updates a database. The SQL query contains a statement such as as CREATE, DROP, INSERT, UPDATE, GRANT, or REVOKE.
The transformation returns NULL rows for SELECT statements that return no results. The rows might contain pass-through port values, SQL error information, or the NUMRowsAffected field.