You often need to enrich one dataset with values from another, such as adding a supplier name, cost center, or booking attribute to a transaction table. In SQL, that usually means choosing the right join pattern and understanding how key matching behaves.
Explain the difference between VLOOKUP and INDEX/MATCH in spreadsheet workflows, and translate that comparison into SQL terms. In your answer, describe when each lookup style is appropriate, what limitations VLOOKUP has compared with INDEX/MATCH, and how those trade-offs relate to join design, key uniqueness, and null handling in PostgreSQL.
Keep your answer practical and interview-focused: define both approaches, compare their flexibility and reliability, and call out the data-shaping implications for many-to-one lookups. You do not need to write a query, but you should connect the concept to SQL data manipulation clearly.
