1. Create an index for the Students table on the email attribute in the university database and provide a point query for which the index is useful.

2. Create an index for the Enroll table on the grade attribute in the university database and provide a range query for which the index is useful.

3. Databases usually contain large amounts of data and a DBMS is required to read data from disk whenever a query is executed. A database index is a data structure that

   improves the speed of data retrieval operations by enabling the DBMS to read only a subset of all data from disk when answering a query.