Interview Prep

Mid-level

• What is the difference between a clustered and a non-clustered index?
  Concepts Very frequent SQL clustered index non-clustered index
• Write a query using window functions to rank employees by salary within each department.
  Coding Very frequent SQL window functions RANK
• Describe a time you designed a database schema from scratch for a new feature.
  Behavioural Frequent SQL schema design normalisation
• When would you choose normalisation over denormalisation, and vice versa?
  SystemDesign Frequent SQL normalisation denormalisation