Concurrent transactions-backup and recovery, Database Management System

Representing complex relationship among data

A database may contain varieties of data interrelated to each other in numerous ways. A DBMS must have the capability to represent a variety of relationships between the data as well as to update and retrieve related data simply and efficiently.

Improved Security

Data is essential to any organisation and also confidential. In a shared system the multiple users share the data, all information has not been shared by all users. For instance, the salary of the employees has not been visible to anyone other than the department dealing in this. Therefore, database should be protected from unauthorised users. This is done by Database Administrator (DBA) by giving the usernames and passwords only to authorised users as well as granting privileges or the type of operation allowed. This is complete by using security and authorisation subsystem. Only authorised clients may use the database and their access types can be restricted to only retrieval, update, insert or delete or any of these. Let us take example; the Branch Manager of any company may have access to all data while the Sales Assistant may not have access to salary details.

Improved Backup and Recovery

A file-based system may fail to give measures to protect data from system failures. This lies only on the user by taking backups intermittently. DBMS gives facilities for recovering the hardware and software failures. A recovery and backup subsystem is liable for this. In case a program fails, it restores the database to a state in which it was before the implementation of the program.

Support for concurrent transactions

A transaction is defined as the unit of work. For illustration, a bank may be there in a transaction where an amount of Rs.5000/- is transmitted from account X to account Y. A DBMS also transmit multiple transactions to occur concurrently.

Posted Date: 3/5/2013 4:52:19 AM | Location : United States







Related Discussions:- Concurrent transactions-backup and recovery, Assignment Help, Ask Question on Concurrent transactions-backup and recovery, Get Answer, Expert's Help, Concurrent transactions-backup and recovery Discussions

Write discussion on Concurrent transactions-backup and recovery
Your posts are moderated
Related Questions
Describe about Object oriented design Object oriented design is concerned with developing an object oriented model of a software system to implement known requirements. Many OO

What is advantage of two-way association? Two-way association advantages are following: a) Independent of the classes. b) Useful for existing predefined classes that are

what is Nested relational model? Explain with examples.

Boyce-Code Normal Form (BCNF) A relationship is said to be in BCNF if it is already in 3NF and the left hand side of each dependency is a candidate key. A relation who is in 3N

Client Server Databases- The concept behind the Client/Server systems is simultaneous, cooperative processing. It is an approach that presents a one systems view from a user's vie

Availability: A site having the copy of a replicated relation fails, even then the relation may be found in another site. Therefore, the system may carry on to process at least th


Benefits of using heuristics

What kind of advantages to copying records from one table to another? -) When an algorithm that modifies a table is used after that it's safer to work with the copy -) When

Attribute Preservation This is a easy and obvious necessity that includes preserving all the attributes that were there in the relation that is being decomposed.