Views-data control, Database Management System

Assignment Help:

Views

A view is like a window by which data from tables can be changed or viewed. The table on which a view is based is known as Base table. The view is stored as a SELECT statement in the data dictionary. When the user needs to retrieve data, using view. Then the following steps are defined.

1)  View definition is finding from data dictionary table. For example, the view definitions in oracle are to be finding from table name USER-VIEWS.

2)  Checks access privileges for the view base table.

3)  Changes the view query into an equivalent operation on the underlying base table

 

 


Related Discussions:- Views-data control

Explain the need for the bcnf normal form, Surgeons identified by doctor ID...

Surgeons identified by doctor ID (DOCID) operate on patients identified by patient ID (PATID) in operating theaters identified by room numbers (ROOMNO). Each surgeon can operate on

What is indexed sequential file organization, What is indexed sequential fi...

What is indexed sequential file organization? What are the applications of this organization?  Ans: An index file can be employed to effectively overcome the problem of storing

The result of the union operation between r1 and r2, The result of the UNIO...

The result of the UNION operation between R1 and R2 is a relation that includes? The result of the operation between R1 and R2 includes all the tuples of R1 and R2 which have c

Which sorting technique is used to sort databases, Which sorting technique ...

Which sorting technique is used to sort databases, whose sizes are very big?  Give one such algorithm.  Why do sorting techniques like quicksort, insertion sort, etc.  not applied

Define upgrade and downgrade, Define upgrade and downgrade? It gives a ...

Define upgrade and downgrade? It gives a mechanism for conversion from shared lock to exclusive lock is called as upgrade. It gives a mechanism for conversion from exclusive

Entity integrity, Before defines the second type of integrity constraint, v...

Before defines the second type of integrity constraint, viz., Entity Integrity, we should be well-known with the concept of NULL. Mostly, NULL is intended as a basis for dealing

Queries, Find the names of all Albums that have more than 30 tracks. Result...

Find the names of all Albums that have more than 30 tracks. Result: (name: varchar(255))

Explain the check clause, Explain the Check Clause The CHECK clause is ...

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

Er diagram, Design a generalization–specialization hierarchy for a motor-ve...

Design a generalization–specialization hierarchy for a motor-vehicle sales company. The company sells motorcycles, passenger cars, vans, and buses. Justify your placement of attrib

Define the terms entity type and entity set, Define the terms i) Entity typ...

Define the terms i) Entity type ii) Entity set Entity type: An entity type describes a collection of entities that have the similar attributes. Entity set: The set of all en

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