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!
If R1 and R2 are two union compatible relations or functions, then the result of R3 = R1 ∩R2 is the relation that contains all tuples that are in both the relations In other words, R3will have tuples such that R3 = {t | R1 ∋ t ∧ R2 ∋ t}.
Example:
R1
A
B
A1
B1
A2
B2
A3
B3
A4
B4
R2
A7
B7
X
Y
R3 = R1 ∩ R2 is
Note: 1) Intersection is an associative operation, i.e., R1 ∩ (R2 ∩ R3) = (R1 ∩ R2) ∩ R3
2) Intersection is a commutative operation, i.e., R1 ∩ R2 = R2 ∩ R1
What is the way a particular application views the data from the database that the application uses? Sub schema is the way a particular application views the data from the data
What Is Recovery? During the life of a transaction, i.e., a after the start of a transaction but before the transaction commits, various changes may be made in a database state
coventions for displaying an ER schema as ER diagram
Define the terms i) DDL ii) DML DDL: Data base schema is specified by a set of definitions expressed by a special language known as a data def
Describe the Menu based interfaces for web clients or browsing? Menu-Based Interfaces for Web Clients or Browsing - These interfaces present the user along with lists of option
What is the use of sub queries? A sub query is a select-from-where expression that is nested with in another query. A common use of sub queries is to do tests for set membershi
in an organization several projects are undertaken. Each project can employ one or more employees. Each employee can work on one or more projects. Each project is undertaken on the
It is mandatory that for every table in the LDB hierarchy there should exist one GET statement in the report. False. It is not essential.
Explain Growing Phase of locking Growing Phase: In this phase the transaction can only obtain locks, but cannot release any lock. The transaction enters the growing phase as so
What is Natural Language Interfaces? Natural Language Interfaces - These interfaces accept requests written within English or a few other language and attempt to "understand" t
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: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd