Structure of distributed database, Database Management System

Structure Of Distributed Database: A distributed database system haves of a collection of sites, each of which keeps a local databases system. Every site is able to process local transactions, the transactions that access data only in that one site. In addition, a site may participate in the implementation of global transactions, those transactions that access data at various sites.

The execution of global transactions on the distributed architecture needs communication between the sites. Figure illustrates a representative distributed database system architecture having transactions. Please note that both the transactions shown are global in nature as they need data from both the sites.

                    2207_Structure Of Distributed Database.png

                                   Figure: Distributed Database Schema and Transactions

   Some of the key issues including DDBMS are:

  • How the data is distributed?
  • Is this data distribution unseen from the general users?
  • How are the integration of data and its control including security managed globally and locally?
  • How are the distributed database related?

The sites in a distributed system can be related physically in a variety of ways. The several topologies are represented as graphs whose nodes correspond to sites. An edge from node A to node B communicates to a direct connection among the two sites.

Some of the most common connection structures are depicted in Figure. The main differences between these configurations involve:

  • Installation cost. The cost of physically connecting the sites in the system
  • Communication cost. The cost in time and money to send a message through site A to site B.
  • Reliability. The frequency with which a site or link fails.
  • Availability. The degree to which data can be accessed despite failure of some links or sites.

These differences play an vital role in choosing the appropriate mechanism for handling the distribution of data The sites of a distributed database system may be distributed physically either over a huge geographical area (such as all over India), or a small geographical area such as a one building or a number of adjacent buildings). The former type of network is based on broad area network, whereas the latter uses local-area network.

Posted Date: 3/12/2013 5:50:51 AM | Location : United States

Related Discussions:- Structure of distributed database, Assignment Help, Ask Question on Structure of distributed database, Get Answer, Expert's Help, Structure of distributed database Discussions

Write discussion on Structure of distributed database
Your posts are moderated
Related Questions
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

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

Consider the following relational scheme: R (a,b,c,d,e,f) and its corresponding set of FDs {d→ a, be → c, ac → e, b → f, f → d, a → c}. a. Is the following decomposition i) non

Identification of concurrency Identification of concurrency: Dynamic model identifies concurrency. Two objects are said to be parallel (concurrent) if they can receive events a

Create a table according to given data:  AmbulanceDriver(Driver_Number#, Name, Address, Birth_Date) AmbulanceDriverTeam(Team_Number#, Driver_Number#, Join_Date, Lea

how to implement hyrise in C plus plus

i need help for assignment ..

Explain Authorization and Integrity Manager ? Authorization and Integrity Manager: Tests for the satisfaction of integrity constraints and checks the authority of users to acce

Attributes attached to an entity can be of various types. Simple The attribute that cannot be further separated into smaller parts and shows the basic meaning is known as a

How to use Oracle