Question

A developer notices that a frequently run query filtering customer records by email address is slow against a large relational table. The database already stores all rows correctly, but read performance on this specific query is poor. Which database feature should be applied to the email column to improve the query's read performance without changing the stored data?

Accepted Answer

Create an index on the email column

Answer

Add a foreign key constraint on the email column

Answer

Denormalize the table by merging it with the orders table

Answer

Convert the table's storage to a columnar Parquet file