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!
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 needs may still have some undesirable characteristics such as data redundancy, and anomalies.
What are these undesirable characteristics and how can we eliminate them from the database system? This part is an attempt to answer this question. Though, please note that most of these undesirable properties do not arise if the database modelling has been carried out very carefully using some method like the Entity-Relationship Model. It is still important to use the methods in this unit to check the database that has been acquired and ensure that no mistakes have been made in modeling.
The central thought in these discussions is the concept of Database integrity, the notion of functional dependency, which rely on understanding the semantics of the data and which deals with what information in a relation is dependent on what other information in the relation. Our prime objective in this section is to describe the concept of data integrity, functional dependence and then describes normal forms using functional dependencies and using other types of data dependencies.
OBJECTIVES
After reading this section you should be able to
What is Data Storage? The storage structures and access methods used by database system are specified by a set of explanation in a special type of DDL called data storage-defin
Software failures : In such cases, a software error abruptly stops the implementation of the current transaction (or all transactions), therefore leading to losing the state of pr
Explain the steps for reduction of E-R model into relational model. Ans:(a) Entity set in E-R model will be considered as table name in relational Model. (b) Attributes of e
File Organisation In Dbms Introduction Databases are used to store information. Usually, the principal operations we have to perform on database are those relating to:
Project Description: Critical Project for VMware Technical support. VMWare ESXi 5.1 support for upgradation and migration problem. Technical expert of Vmware needed. Sk
(A) For the relation; CarSales (RegNo, BuyerName, Address, SalesPerson, Make, Model, Commission) The following functional dependences hold, RegNo _ID à Make, Model Reg
Explain Alternate key? Alternate Key - All the candidate keys except primary key are known as alternate keys.
After the completion of the logical model the physical model is to be made. The oracle 10 G will be used as a database server and all the tables with their column are created and i
Describe the functions and features of foreign key? Foreign Key : The primary key of one file or table that is implanted in another file or table to implement the relationships
what is file organization? what are file organization techniques.explain in detail? explain random file organization technique, multikey file organization technique?what is indexin
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