Removed duplicated code on S3ToRedshiftOperator (#18671)

airflow/providers/amazon/aws/transfers/s3_to_redshift.py

@@ -130,30 +130,6 @@ def _build_copy_query(self, copy_destination: str, credentials_block: str, copy_
                     {copy_options};
         """
 
-    def _get_table_primary_key(self, postgres_hook):
-        sql = """
-            select kcu.column_name
-            from information_schema.table_constraints tco
-                    join information_schema.key_column_usage kcu
-                        on kcu.constraint_name = tco.constraint_name
-                            and kcu.constraint_schema = tco.constraint_schema
-                            and kcu.constraint_name = tco.constraint_name
-            where tco.constraint_type = 'PRIMARY KEY'
-            and kcu.table_schema = %s
-            and kcu.table_name = %s
-        """
-
-        result = postgres_hook.get_records(sql, (self.schema, self.table))
-
-        if len(result) == 0:
-            raise AirflowException(
-                f"""
-                No primary key on {self.schema}.{self.table}.
-                Please provide keys on 'upsert_keys' parameter.
-                """
-            )
-        return [row[0] for row in result]
-
     def execute(self, context) -> None:
         postgres_hook = PostgresHook(postgres_conn_id=self.redshift_conn_id)
         conn = S3Hook.get_connection(conn_id=self.aws_conn_id)