Which two are true about the Oracle database methodology?

The Oracle Database time model should be used to find the database and instance areas most in need of tuning.

Tuning activities should stop once the user is satisfied with performance.

Tuning activities should stop once agreed service levels for performance have been met.

The database instance memory should always be tuned before tuning any file systems.

SQL statements should always be tuned before tuning any file systems.

The alert log should be used to find the database and instance areas most in need of tuning.