Increased overheads on update-data replication, Database Management System

Assignment Help:

Increased overheads on update: On the drawbacks side, it will need the system to ensure that all replicas of a relation are consistent. This shows that all the replicas of the relation require to be updated at the similar time, resulting in increased overheads. For instance, in a banking system, if account information is replicated at several sites, it is essential that the balance in a particular account should be the similar at all sites.

The problem of controlling concurrent updates by various transactions to replicated data is more difficult than the centralised approach of concurrency control. The management of replicas of relation can be simplified by deciding one of the replicas as the primary copy. For instance, in a banking system, the primary copy of an account may be the site at which the account has been opened. Likewise, in an airline reservation system, the primary copy of the flight may be related with the site at which the flight originates.


Related Discussions:- Increased overheads on update-data replication

Central database schema, Consider an information system designed for an onl...

Consider an information system designed for an online company which provides IT products and services. These include desktops, laptops, networking products, IT books, parts, and te

Define the term- having clause and a where clause, What is the difference ...

What is the difference between a HAVING CLAUSE and a WHERE CLAUSE? HAVING CLAUSE - HAVING CLAUSE is used only with SELECT statement. - It is normally used in a GROUP BY

Linked list, what is difference between circular inked lust and grunded lin...

what is difference between circular inked lust and grunded linked list

Key to represent relationship between tables is called, Key to represent re...

Key to represent relationship amongs tables is called ? A Key that represent the relationship between tables is called Foreign Key.

In how many parts events are classified, In how many parts events are class...

In how many parts events are classified Events are classified as four types in UML 1.  Signals 2.  Calls 3.  Passing of Time 4.  Change in State

Functional Dependencies, What exactly is the concept of Functional Dependen...

What exactly is the concept of Functional Dependencies? And how do we associate this concept with the logic of Super-keys, Candidate Keys, etc? Given Relation R(A,B,C,D,E) with de

What is foreign key, What is foreign key? A relation schema r1 derived ...

What is foreign key? A relation schema r1 derived from an ER schema may contain among its attributes the primary key of another relation schema r2.this attribute is known as a

What is meant by log-based recovery, What is meant by log-based recovery? ...

What is meant by log-based recovery? The most widely used structures for recording database changes is the log. The log is a sequence of log records, recording all the update a

Explain controlled redundancy, Explain controlled redundancy? Controll...

Explain controlled redundancy? Controlled redundancy : The replication of data within the data warehouse for the purposes of improved data access or understand ability.

ERD, A student entity type has the following attributes,name..

A student entity type has the following attributes,name..

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