Assume that “ABC media” has decided to have the relational schema for their database. Schema: 1. Video (videoCode, videoLength) 2. Model (modelNo, width, height, weight, depth, screenSize) 3. Site (siteCode, type, address, phone) 4. DigitalDisplay (serialNo, schedulerSystem, modelNo) Foreign key:modelNo references Model (modelNo) 5. Client (clientId, name, phone, address) 6. TechnicalSupport (empId, name, gender) 7. Administrator (empId, name, gender) 8. Salesman (empId, name, gender) 9. AirtimePackage (packageId, class, startDate, lastDate, frequency,videoCode) 10. AdmWorkHours (empId, day, hours)Foreign key: empId references Administrator (empId) 11. Broadcasts (videoCode, siteCode)Foreign key: videoCode references Video (videoCode)Foreign key: siteCode references Site (siteCode) 12. Administers (empId, siteCode)Foreign key: empId references Administrator (empId)Foreign key: siteCode references Site (siteCode) 13. Specializes (empId, modelNo)Foreign key: empId references TechnicalSupport (empId)Foreign key: modelNo references Model (modelNo) 14. Purchases (clientId, empId, packageId, commissionRate)Foreign key: clientId references Client (clientId)Foreign key: empId references Salesman (empId)Foreign key: packageId references AirtimePackage (packageId) 15. Locates (serialNo, siteCode)Foreign key: serialNo references DigitalDisplay (serialNo)Foreign key: siteCode references Site (siteCode Task: Given the above database schema, write Relational Algebra (RA) statements to answer the following question 8. Find the names of all employees (including administrators, salesmen, and technical supports) working in this company. So would number 8 look like this? I want to check my answer, if not tell me why and what the correct response is. ∏name(Administrator) ∪ ∏name(Salesman) ∪ ∏name(TechnicalSupport)

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Related questions

Concept explainers

Question

Assume that “ABC media” has decided to have the relational schema for their database.

Schema:

1. Video (videoCode, videoLength)

2. Model (modelNo, width, height, weight, depth, screenSize)

3. Site (siteCode, type, address, phone)

4. DigitalDisplay (serialNo, schedulerSystem, modelNo) Foreign key:modelNo references Model (modelNo)

5. Client (clientId, name, phone, address)

6. TechnicalSupport (empId, name, gender)

7. Administrator (empId, name, gender)

8. Salesman (empId, name, gender)

9. AirtimePackage (packageId, class, startDate, lastDate, frequency,videoCode)

10. AdmWorkHours (empId, day, hours)Foreign key: empId references Administrator (empId)

11. Broadcasts (videoCode, siteCode)Foreign key: videoCode references Video (videoCode)Foreign key: siteCode references Site (siteCode)

12. Administers (empId, siteCode)Foreign key: empId references Administrator (empId)Foreign key: siteCode references Site (siteCode)

13. Specializes (empId, modelNo)Foreign key: empId references TechnicalSupport (empId)Foreign key: modelNo references Model (modelNo)

14. Purchases (clientId, empId, packageId, commissionRate)Foreign key: clientId references Client (clientId)Foreign key: empId references Salesman (empId)Foreign key: packageId references AirtimePackage (packageId)

15. Locates (serialNo, siteCode)Foreign key: serialNo references DigitalDisplay (serialNo)Foreign key: siteCode references Site (siteCode

Task: Given the above database schema, write Relational Algebra (RA) statements to answer the
following question

8. Find the names of all employees (including administrators, salesmen, and technical
supports) working in this company.

So would number 8 look like this? I want to check my answer, if not tell me why and what the correct response is.
∏name(Administrator) ∪ ∏name(Salesman) ∪ ∏name(TechnicalSupport)

Expert Solution

Step 1

yes,

Step by step

Solved in 2 steps

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

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