Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE technician (Name VARCHAR, technician_id VARCHAR)
TABLE: CREATE TABLE repair_assignment (Name VARCHAR, technician_id VARCHAR)

### Question ###
List the names of technicians who have not been assigned to repair machines.

### Accurate SQL ###

SELECT Name FROM technician WHERE NOT technician_id IN (SELECT technician_id FROM repair_assignment)