DATABASE SYSTEM CONCEPTS LCPO
DATABASE SYSTEM CONCEPTS LCPO
7th Edition
ISBN: 9781265586577
Author: SILBERSCHATZ
Publisher: MCG
Expert Solution & Answer
Book Icon
Chapter 15, Problem 21E

Explanation of Solution

Extending the hash-join algorithm:

  • The hash-join is used to compute the natural join of two relations.
  • The hash-join algorithm can be extended to compute the natural left outer join by,
    • Padding the tuple tr in the probe relation with nulls, if no matching tuple is found in the build relation’s hash partition.
    • Include this null padded tuple in the result as well.
  • The hash-join algorithm can be extended to compute the natural right outer join by,
    • Keeping a Boolean flag with each tuple in the current build relation partition which resides in memory.
    • Set it whenever any probe relation tuple matches the above tuple.
    • Finally, Pad with null those tuples which do not have their flags set and include them in the result.
  • The hash-join algorithm can be extended to compute the natural full outer join by performing natural left outer join and natural right outer join together.

Example:

Consider the customer and depositor relations given below:

customer_namecustomer_addresscustomer_city
AdamPark StreetBrooklyn
EveMain RoadRye
JohnBell CrossHarrison
JaneSand HillWoodside
TomWalnutPittsfield
JerryAlmaAlabama

Blurred answer
Students have asked these similar questions
Hands-On Assignments Part II Assignment 1-5: Querying the DoGood Donor Database Review the DoGood Donor data by writing and running SQL statements to perform the following tasks: 1. List each donor who has made a pledge and indicated a single lump sum payment. Include first name, last name, pledge date, and pledge amount. 2. List each donor who has made a pledge and indicated monthly payments over one year. Include first name, last name, pledge date, and pledge amount. Also, display the monthly payment amount. (Equal monthly payments are made for all pledges paid in monthly payments.) 3. Display an unduplicated list of projects (ID and name) that have pledges committed. Don't display all projects defined; list only those that have pledges assigned. 4. Display the number of pledges made by each donor. Include the donor ID, first name, last name, and number of pledges. 5. Display all pledges made before March 8, 2012. Include all column data from the DD PLEDGE table.
Write a FancyCar class to support basic operations such as drive, add gas, honk horn, and start engine. FancyCar.java is provided with method stubs. Follow each step to gradually complete all methods. Note: This program is designed for incremental development. Complete each step and submit for grading before starting the next step. Only a portion of tests pass after each step but confirm progress. The main() method includes basic method calls. Add statements in main() as methods are completed to support development mode testing. Step 0. Declare private fields for miles driven as shown on the odometer (int), gallons of gas in tank (double), miles per gallon or MPG (double), driving capacity (double), and car model (String). Note the provided final variable indicates the gas tank capacity of 14.0 gallons. Step 1 (2 pts). 1) Complete the default constructor by initializing the odometer to five miles, tank is full of gas, miles per gallon is 24.0, and the model is "Old Clunker". 2)…
Find the error: daily_sales = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0] days_of_week = ['Sunday', 'Monday', 'Tuesday',                     'Wednesday', 'Thursday', 'Friday',                     'Saturday'] for i in range(7):         daily_sales[i] = float(input('Enter the sales for ' \                                      + day_of_week[i] + ': ')
Knowledge Booster
Background pattern image
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Database System Concepts
Computer Science
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:McGraw-Hill Education
Text book image
Starting Out with Python (4th Edition)
Computer Science
ISBN:9780134444321
Author:Tony Gaddis
Publisher:PEARSON
Text book image
Digital Fundamentals (11th Edition)
Computer Science
ISBN:9780132737968
Author:Thomas L. Floyd
Publisher:PEARSON
Text book image
C How to Program (8th Edition)
Computer Science
ISBN:9780133976892
Author:Paul J. Deitel, Harvey Deitel
Publisher:PEARSON
Text book image
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781337627900
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning
Text book image
Programmable Logic Controllers
Computer Science
ISBN:9780073373843
Author:Frank D. Petruzella
Publisher:McGraw-Hill Education