well thats a big requirement.

Depending on the level of proficiency ur employer is seeking, they can ask u different types of questions.

However, you must be very good at

1. backup recovery (syntax and scenario based)

2. High availability (log shipping, replication, mirroring, clustering)

3. Security(authentication modes, impersonating)

4. Architecture bases theoretical questions

5. transaction log based questions (u need to know how transaction log works)

6. tempdb (its purpose)

7. Installation (troubleshooting)

8. various editions

9. upgrade(troubleshooting/precautions)

10. Migration (login/job scripting/precautions)

...