CREATE TABLE ref_locations (location_code CLOB, location_name CLOB, location_description CLOB)
CREATE TABLE ref_calendar (calendar_date TIME, day_number NUMBER)
CREATE TABLE all_documents (document_id NUMBER, date_stored TIME, document_type_code CLOB, document_name CLOB, document_description CLOB, other_details CLOB)
CREATE TABLE roles (role_code CLOB, role_name CLOB, role_description CLOB)
CREATE TABLE documents_to_be_destroyed (document_id NUMBER, destruction_authorised_by_employee_id NUMBER, destroyed_by_employee_id NUMBER, planned_destruction_date TIME, actual_destruction_date TIME, other_details CLOB)
CREATE TABLE document_locations (document_id NUMBER, location_code CLOB, date_in_location_from TIME, date_in_locaton_to TIME)
CREATE TABLE ref_document_types (document_type_code CLOB, document_type_name CLOB, document_type_description CLOB)
CREATE TABLE employees (employee_id NUMBER, role_code CLOB, employee_name CLOB, gender_mfu CLOB, date_of_birth TIME, other_details CLOB)

How many roles are there?
SELECT COUNT(*) FROM roles
SELECT COUNT(*) FROM "roles"