Database Systems: Design, Implementation, & Management
Database Systems: Design, Implementation, & Management
11th Edition
ISBN: 9781285196145
Author: Steven, Steven Morris, Carlos Coronel, Carlos, Coronel, Carlos; Morris, Carlos Coronel and Steven Morris, Carlos Coronel; Steven Morris, Steven Morris; Carlos Coronel
Publisher: Cengage Learning
bartleby

Concept explainers

Expert Solution & Answer
Book Icon
Chapter 10, Problem 2P

Explanation of Solution

Concurrency control:

The purpose of concurrency control is to ensure the serializability of transaction in a multiuser database environment and it is the process of coordinating the simultaneous execution.

Common problems with concurrent transaction execution:

Concurrency transaction is one or more transactions are processed on same time. During the concurrency transaction execution the following problems can occur in the transaction. They are:

  • Lost updates
  • Uncommitted data
  • Inconsistent retrievals

Lost updates:

A data can be lost when the two different transactions want to update same field or row within the database at the same time.

  • For example: if the transactions “T1” and “T2” want to update the same element and one of the updates is lost or overwritten by other transactions.

Uncommitted data:

The data of the transactions are not committed when the transactions are executed concurrently...

Blurred answer
Students have asked these similar questions
• Solve the problem (pls refer to the inserted image)
Write .php file that saves car booking and displays feedback.  There are 2 buttons, which are <Book it> <Select a date>. <Select a date> button gets an input from the user, start date and an end date. Book it button can be pressed only if the start date and ending date are chosen by the user. If successful, it books cars for specific dates, with bookings saved. Booking should be in the .json file which contains all the bookings, and have the following information: Start Date. End Date. User Email. Car ID. If the car is already booked for the selected period, a failure message should be displayed, along with a button to return to the homepage. In the booking.json file, if the Car ID and start date and end date matches, it fails Use AJAX: Save bookings and display feedback without page refresh, using a custom modal (not alert).
Write .php file with the html that saves car booking and displays feedback.  Booking should be in the .json file which contains all the bookings, and have the following information: Start Date. End Date. User Email. Car ID. There are 2 buttons, which are <Book it> <Select a date> Book it button can be pressed only if the start date and ending date are chosen by the user. If successful, book cars for specific dates, with bookings saved. If the car is already booked for the selected period, a failure message should be displayed, along with a button to return to the homepage. Use AJAX: Save bookings and display feedback without page refresh, using a custom modal (not alert). And then add an additional feature that only free dates are selectable (e.g., calendar view).
Knowledge Booster
Background pattern image
Computer Science
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781305627482
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning
Text book image
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781285196145
Author:Steven, Steven Morris, Carlos Coronel, Carlos, Coronel, Carlos; Morris, Carlos Coronel and Steven Morris, Carlos Coronel; Steven Morris, Steven Morris; Carlos Coronel
Publisher:Cengage Learning