Question: SQL supports four isolation-levels and two access-modes, for a total of eight combinations of isolation-level and access-mode. Each combination implicitly defines a class of transactions;

SQL supports four isolation-levels and two access-modes, for a total of eight combinations of isolation-level and access-mode. Each combination implicitly defines a class of transactions; the following questions refer to these eight classes:
1. For each of the eight classes, describe a locking protocol that allows only transactions in this class. Does the locking protocol for a given class make any assumptions about the locking protocols used for other classes? Explain briefly.
2. Consider a schedule generated by the execution of several SQL transactions. Is it guaranteed to be conflict-serializable? to be serializable? to be recoverable?
3. Consider a schedule generated by the execution of several SQL transactions, each of which has READ ONLY access-mode. Is it guaranteed to be conflict-serializable? to be serializable? to be recoverable?
4. Consider a schedule generated by the execution of several SQL transactions, each of which has SERIALIZABLE isolation-level. Is it guaranteed to be conflictserializable? to be serializable? to be recoverable?
5. Can you think of a timestamp-based concurrency control scheme that can support the eight classes of SQL transactions?

Step by Step Solution

★★★★★

3.35 Rating (161 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer

Step: 1 Unlock

1 The classes SERIALIZABLE REPEATABLE READ and READ COMMITTED rely on the assumption that other classes obtain exclusive locks before writing objects ... View full answer

Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock

Step: 3 Unlock

Document Format (1 attachment)

960-C-S-D (2492).docx

120 KBs Word File

Students Have Also Explored These Related Databases Questions!

What are the four ANSI transaction isolation levels? What type of reads does each level allow?

Consider a database with the following schema: Suppliers(sid: integer, sname: string, address: string) Parts(pid: integer, pname: string, color: string) Catalog(sid: integer, pid: integer, cost:...

Show the SQL statement necessary to set the transaction isolation level to serializable for an entire session.

MATHEMATICS FOR MACHINE LEARNING Marc Peter Deisenroth A. Aldo Faisal Cheng Soon Ong Contents Foreword 1 Part I Mathematical Foundations 9 1 Introduction and Motivation 11 1.1 Finding Words for...

Refer to the 2013 annual report of JB Hi-Fi Limited on its website, ww.jbhifi.com.au, and answer the following questions: 1. List the subsidiary companies in the JB Hi-Fi Group. 2. What is the value...

Refer to the 2013 annual report of JB Hi-Fi Limited on its website, ww.jbhifi.com.au, and answer the following questions: 1. What are the different types of revenues generated by the consolidated...

1. Daniel Dimwit sees an advertisement for a toaster oven at Target for the price of $49.00. When he gets to Target they are all sold out. Sears has the same toaster oven for $60.00. Can Mr. Dimwit...

2012 Annual Report Our \"bottom line\" ultimately depends on our ability to satisfy all of our stakeholders. Our goal is to balance the needs and desires of our customers, team members, shareholders,...

Match the following columns and select the correct option. Column - I Column - II (a) 6 - 15 pairs of (i) Trygon gill slits (b) Heterocercal (ii) Cyclostomes caudal fin (c) Air Bladder (iii)...

A rectangular box which is open at the top has a capacity of 256 cm. Determine the dimensions of the box such that the least material of construction of the box is required. Use Langrage's method of...

Securitization refers to the practice where a financial institution will Part 2 A . reduce the risk of a stock by issuing it in a stable currency such as the U . S . dollar or Japanese Yen. B . sell...

Disposal personal income a. is the income people spend for personal items such as homes and cars. b. includes transfer payments. c. excludes transfer payments. d. includes personal taxes.

In general, what are data administrations responsibilities to the professional and managerial employees of the company? Concentrate on training, publicity, and liaison tasks.

Defend or refute the following statement: Current IS technologies and practices make having data standards more important than ever before.

What kinds of planning do data administrators have to do regarding data?

Braddock Construction Co.'s stock is trading at $20 a share. Call options that expire in three months with a strike price of $20 sell for $1.50. Which of the following will occur if the stock price...

In a large doll store, 47% of the dolls blink, 56% of the dolls have movable legs and arms, and 23% of the dolls neither blink nor have movable limbs. Find the probability that a doll chosen at...

Well-Being.CA, an online pharmacy, promises to deliver prescriptions to its customers for free. Online consultations with their pharmacists and doctors are also offered. Recently, the company's...