DATABASE SYSTEMS-MINDTAPV2.0
DATABASE SYSTEMS-MINDTAPV2.0
13th Edition
ISBN: 9780357427873
Author: Coronel
Publisher: CENGAGE L
bartleby

Concept explainers

Expert Solution & Answer
Book Icon
Chapter 5, Problem 1RQ

Explanation of Solution

Entity Supertype:

  • The entity supertype is an entity type that has the relation with one or more subtypes and it contains the common attributes of its subtypes.
  • The entity subtype is a grouping of entities type in single entity that shares the common attributes or relationships which are different from other grouping.

Use of entity supertype:

The reason for using entity supertype is to reduce redundant relationships and also reduce the number of nulls.

Example:

The following example demonstrates the “supertype” entity, “subtype” entity, and “discriminator”.

DATABASE SYSTEMS-MINDTAPV2.0, Chapter 5, Problem 1RQ

Explanation:

  • Here, “Employee” entity is a “supertype” entity.
  • “Hourly Employee”, “Salaried Employee”, and “Consultant” are the “Sub type” entities.
  • “Emp_type” is a discriminator to select appropriate “subtype”.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
If a UDP datagram is sent from host A, port P to host B, port Q, but at host B there is no process listening to port Q, then B is to send back an ICMP Port Unreachable message to A. Like all ICMP messages, this is addressed to A as a whole, not to port P on A. (a)  Give an example of when an application might want to receive such ICMP messages. (b)  Find out what an application has to do, on the operating system of your choice, to receive such messages. (c)  Why might it not be a good idea to send such messages directly back to the originating port P on A?
Discuss how business intelligence and data visualization work together to help decision-makers and data users. Provide 2 specific use cases.
This week we will be building a regression model conceptually for our discussion assignment. Consider your current workplace (or previous/future workplace if not currently working) and answer the following set of questions. Expand where needed to help others understand your thinking:  What is the most important factor (variable) that needs to be predicted accurately at work? Why? Justify its selection as your dependent variable.
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: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
Text book image
Oracle 12c: SQL
Computer Science
ISBN:9781305251038
Author:Joan Casteel
Publisher:Cengage Learning
Text book image
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781305627482
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning
Text book image
Principles of Information Systems (MindTap Course...
Computer Science
ISBN:9781285867168
Author:Ralph Stair, George Reynolds
Publisher:Cengage Learning
Text book image
Fundamentals of Information Systems
Computer Science
ISBN:9781305082168
Author:Ralph Stair, George Reynolds
Publisher:Cengage Learning
Text book image
A Guide to SQL
Computer Science
ISBN:9781111527273
Author:Philip J. Pratt
Publisher:Course Technology Ptr