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!
Explain view in RDBMS?
View - A view is a relation (virtual rather than base) and could be used in query expressions, which is, queries can be written by using the view as a relation. Instead, a view is a named table in which is represented, not through its own physically separate stored data, but through its definition in terms of other named tables (base tables or views). The base relations on that a view is based are sometimes known as the existing relations. The definition of a view in a create view statement is stored within the system catalog. The syntax to create a view is:
CREATE [OR REPLACE] VIEW [()] AS
WITH {READ ONLY|CHECK OPTION [CONSTRAINT
]};
Entities Let us first be aware of the question: What are entities? An entity is an object of concern used to show the things in the actual world, e.g., table, car, bo
Relations create the database. They must satisfy various properties, like no duplicate tuples, no ordering of tuples, and atomic attributes, etc. Relations that satisfy these basic
Normalization :It is a process of examine the given relation schemas based on their primary key and Functional Dependencies (FDs) to achieve the properties Minimizing redun
Define the Wait for graph Ans: The wait-for-graph is a directed graph and consist of nodes and directed arcs; the nodes of the graph are active transactions. An arc of the grap
The cross-section of twisted pair The cross-section of each and every strand of the twisted pair is π/4 square mm. A 10-km length of this type of material, with two strands per
What is a view? Make a view of EMP table named DEPT 20, to display the employees in department 20 and their annual salary. Ans: View is a virtual table that does not consist
Explain the Check Clause The CHECK clause is employed to at the end of a CREATE TABLE statement specify table constraints. This is known as table-based constraint because it ap
Differentiate between Key and superkey? Key and superkey - A key a single attribute or a combination of two or more attributes of an entity set in which is used to identify o
What is an E-R model? Draw an E-R Diagram for the company database with following Descriptions? The company is organized within departments. Each department has a unique name a
Describe the statement in SQL which allows to change the definition of a table? In SQL Alter statement is used to allow the changes the definition of a table.
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