I wonder how to deal with a salary raise of an employee ? I see 2 options:

1. Change the value 'wage' in the existing contract
2. make a new contract with the new salary
3. add a raise in the salary calculation (salary rules, etc.)

Option 1 has the advantage that the contract duration stays correct,
Option 2 has the advantage that you could look up in the 'old' contract what the previous salary had been

can anybody advise a best practice?