Subject Area: Databases

Consider a database table Employee whose schema includes two columns JobTitle and Salary. Assume the DBMS stores record pointers in the index records. Consider the following query statements: Q1: select * from Person where JobTitle = 'Lecturer' and Salary > 30000; Q2: select * from Person where JobTitle = 'Lecturer' or Salary > 30000;

discuss how the DBMS processes each query in the following three cases: [1.a] Each of JobTitle and Salary has an index on it. [1.b] Only JobTitle (i.e., not Salary) has an index on it. [1.c] Neither JobTitle nor Salary has an index on it