Concurrent transactions-backup and recovery, Database Management System

Assignment Help:

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.


Related Discussions:- Concurrent transactions-backup and recovery

Example-revoke all on emp from mca12, Example:  //REVOKE ALL ON EMP FROM MC...

Example:  //REVOKE ALL ON EMP FROM MCA12;                              (All permissions will be cancelled) You can also cancel only some of the permissions. Drop: A user-

What are the purpose for having variable length records, What are the purpo...

What are the purpose for having variable length records? What kinds of separator characters are required for each? Variable-Length Records - Variable-length records are thos

Define the basic operations of the relational algebra, Define the basic ope...

Define the basic operations of the relational algebra?     Ans: Basic operators of relational algebra are: 1. Union (∪) - Selects tuples which are in either P or Q or in bot

What do you understand by raid, What do you understand by RAID? Explain RA...

What do you understand by RAID? Explain RAID Level 4 and Level5? RAID - It is stands for Redundant Array of Inexpensive Disks (as named by the inventor), or alternatively Re

Determine candidate and primary key, A video rental company has several bra...

A video rental company has several branches. The data held on each branch is the branch address made up of street, city, state, and zip code, and the telephone number. Ea

What database management system, Company XYZ is an advertising company. It...

Company XYZ is an advertising company. It has its own website but the search facilities offered are not reliable. The company is willing to invest to acquire new machines and sof

Update operations, The Update Operations : Update operations are used fo...

The Update Operations : Update operations are used for altering database values. The constraint violations faced by this operation are logically the similar as the problem faced

What is primary key, What is Primary key? Primary Key - Primary key i...

What is Primary key? Primary Key - Primary key is one of the candidate keys which uniquely identifies each row in the relation.

Differentiate between a unique key and a primary key, Differentiate between...

Differentiate between a unique key and a primary key. - By default, clustered index on column are created by primary key while nonclustered index are created by unique key.

Normalization, Normalize the given relation to 3NF, justifying each step

Normalize the given relation to 3NF, justifying each step

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