What are views explain how views are different from tables, Database Management System

Assignment Help:

What are views? Explain how views are different from tables?

A view in SQL terminology is a one table in which is derived from other tables. These other tables could be base tables or previously described views. A view does not necessarily exist in physical form; it is considered a virtual table, in contrast to base tables, whose tuples are infact stored in the database. This limits the possible update operations in which can be applied to views, but it does not provide any limitations on querying a view. A view represents a variant perspective of a base relation(s). The definition of a view in a form view statement is stored in the system catalog. Any attribute in the view could be updated as long as the attribute is simple and not derived from a computation including two or more base relation attribute. View that includes a join may or may not be updatable. Such views are not updatable if they do not include the primary keys of the base relations.


Related Discussions:- What are views explain how views are different from tables

Explain the concept of deadlock, Question: In a multi-user database env...

Question: In a multi-user database environment, locking mechanisms can be used to solve the three basic problems of concurrency. On the other hand, however, locking may also le

Mis, explain various steps uses in evaluation and maintenance of MIS.

explain various steps uses in evaluation and maintenance of MIS.

Explain the relational completeness, Explain the Relational Completeness ...

Explain the Relational Completeness Codd described the term relational completeness to consider to a language that is complete with respect to first-order predicate calculus ex

Fire department, The State of Newyork certifies firefighters throughout sta...

The State of Newyork certifies firefighters throughout state keep track all of them, as well as the state’s of fire departments. Each fire department has unique department number

multiple-mode locks, Multiple-mode locks : It offers two locks: exclusive ...

Multiple-mode locks : It offers two locks: exclusive locks and shared locks. But why do we require these two locks? There are a lot of transactions in the database system that neve

Difference among a database schema and a database state, What is the differ...

What is the difference among a database schema and a database state? The collection of information stored in database at particular moment in time is known as database state a

Special comparison operator used in where clause-dml, Special comparison op...

Special comparison operator used in where Clause a.   between. ...and...It gives range among two values (inclusive) Example: SELECT ENAME, SAL FROM EMP WHERE SAL BETWE

Log, what is the need of a log in dbms

what is the need of a log in dbms

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd