Questions from Database Systems

Q: ABC Markets sell products to customers. The relational diagram shown in

ABC Markets sell products to customers. The relational diagram shown in Figure P10.6 represents the main entities for ABC’s database. Note the following important characteristics: &a...

Q: Create a simple transaction log (using the format shown in Table

Create a simple transaction log (using the format shown in Table 10.13) to represent the actions of the two previous transactions.

Q: Assuming that pessimistic locking is being used, but the two-

Assuming that pessimistic locking is being used, but the two-phase locking protocol is not, create a chronological list of the locking, unlocking, and data manipulation activities that would occur dur...

Q: Write the SQL code to calculate the ASSIGN_CHARGE values in

Write the SQL code to calculate the ASSIGN_CHARGE values in the ASSIGNMENT table in the Ch07_ConstructCo database. (See Figure P7.1.) Note that ASSIGN_CHARGE is a derived attribute that is calculated...

Q: Assuming that pessimistic locking with the two-phase locking protocol is

Assuming that pessimistic locking with the two-phase locking protocol is being used, create a chronological list of the locking, unlocking, and data manipulation activities that would occur during the...

Q: SELECT EMP_LNAME, EMP_FNAME, EMP_

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; What is the likely data sparsity of the EMP_SEX column?

Q: Given the following query SELECT P_CODE, P

Given the following query SELECT P_CODE, P_PRICE FROM PRODUCT WHERE P_PRICE >= (SELECT AVG(P_PRICE) FROM PRODUCT); Should you create an index? Why or why not? Figure P11.7 The Ch11_SaleCo ER...

Q: SELECT P_CODE, SUM(LINE_UNITS)

SELECT P_CODE, SUM(LINE_UNITS) FROM LINE GROUP BY P_CODE HAVING SUM (LINE_UNITS) > (SELECT MAX(LINE_UNITS) FROM LINE); What is the likely data sparsity of the LINE_UNITS column?

Q: SELECT P_CODE, SUM(LINE_UNITS)

SELECT P_CODE, SUM(LINE_UNITS) FROM LINE GROUP BY P_CODE HAVING SUM (LINE_UNITS) > (SELECT MAX(LINE_UNITS) FROM LINE); Should you create an index? If so, what would the index column(s) be, and why...

Q: SELECT P_CODE, SUM(LINE_UNITS)

SELECT P_CODE, SUM(LINE_UNITS) FROM LINE GROUP BY P_CODE HAVING SUM (LINE_UNITS) > (SELECT MAX(LINE_UNITS) FROM LINE); Should you create an index on P_CODE? If so, write the SQL command to create t...