Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
UNION
If R1 and R2 are two union compatible relations then R3 = R1 ∪ R2 is the relation having tuples that are either in R1 or in R2 or in both.
In case, R3 will have tuples such that R3 = {t | R1 ∋ t ∨ R2 ∋ t}.
Example
R1
X
Y
A1
B1
A7
B7
A2
B2
A4
B4
R2
A
B
A3
B3
R3 = R1 ∪ R2 is
Q
Note: 1) Union is a commutative operation, i.e, R ∪ S = S ∪ R.
2) Union is an associative operation, i.e.
R ∪ (S ∪ T) = (R ∪ S) ∪ T.
1. Create the tables for the play-scheme database as specified in the TMA. 2. Enter the data as given in the spreadsheet. 3. Create queries to retrieve specified information
How to define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a
Differentiate between Procedural and non procedural languages ? Procedural and non procedural languages - A procedural language specifies the operations to be performed on th
The definition of the classes and operation can often be adjusted to increase the amount of inheritance". Justify the above statement. Adjustment of Inheritance The def
Illustrate the class diagram for class room scheduling system If in any college, the number of classrooms are limited which have to be allocated to various classes and instruct
Question 1 Explain ER model Question 2 What are the characteristics of a computer provided information? Question 3 What are facts and guidelines to be considered when se
What are the disadvantages of file-processing system? Ans: The Disadvantages of File-Processing System a. Data redundancy and inconsistency - Data redundancy means not nece
What does the extract statement do in extract datasets? The data is written to virtual memory by extract commands.
Give the limitations of SQL authorization. The code for checking authorization becomes intermixed with the rest of the application code. Implementing authorization by applic
OBJECTIVES After going through this unit you should be capable to: Explain the File Based system and its limitations; Explain the structure of DBMS; Explain the
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd