Expert Answers

Find the solutions to Problems 1 and 2 based on the following query:

SELECT         EMP_LNAME, EMP_FNAME, EMP_AREACODE, EMP_SEX

FROM            EMPLOYEE

WHERE         EMP_SEX = ‘F’ AND EMP_AREACODE = ‘615’

ORDER BY   EMP_LNAME, EMP_FNAME;

1.   What is the likely data sparsity of the EMP_SEX column?

2.   What indexes should you create? Write the required SQL commands.

3. Using Table 11.4 as an example, create two alternative access plans. Use the following assumptions:

a. There are 8,000 employees.

b. There are 4,150 female employees.

c. There are 370 employees in area code 615.

d. There are 190 female employees in area code 615.