Distributed DBMS Database Environments
performed on the clients. Remote Data Client-Server Architecture. Client. Server. Presentation application network database server. DB server client. Usual distribution: .. relationships among heterogeneous sources. - source and target . Distributed databases system use a client/server architecture to process information . Each server processes the local query and sends the resulting relation. Each node in a distributed database system can act as a client, a server, or both, depending on the.
The server software is responsible for local The primary types of system architectures for data management at a site, much like information processing include: Architecture SOAdistributive client—serverand centralized information systems processing b.
The client software is responsible for most of more commonly associated with mainframe and the distribution functions; it accesses data midrange computers. This is a catalog and processes all requests that network architecture in which each computer or require access to more than one site.
It also process on the network is either a client or a handles all user interfaces. Servers are powerful computers or processes dedicated to managing disk drives file c. The communications software sometimes in serversprinters print serversor network traffic conjunction with a distributed operating network servers. Clients are PCs or system provides the communication workstations on which users run applications.
This is not strictly part of the DDBMS, but it provides essential Interaction between client and server might communication primitives and services.
The client is responsible for generating a distributed execution plan for a multi-site query or a. The client parses a user query and transaction and for supervising distributed decomposes it into a number of independent execution by sending commands to servers. Each site query is sent to the These commands include local queries and appropriate server site. Each server processes the local query and servers.
- Distributed Database Architecture
- Distributed DBMS - Database Environments
Hence, client software should be sends the resulting relation to the client site. Another function controlled by the c. The client site combines the results of the client or coordinator is that of ensuring sub-queries to produce the result of the consistency of replicated copies of a data item by originally submitted query.
The client must also ensure In this approach, the SQL server has also been the atomicity of global transactions by performing called a transaction server or a database global recovery when certain sites fail. For example, the user may know presented below: Registration Identity of the automobile submit individual sub-queries to the various sites.
November Fall d. State where the automobile is been Registration also allows information about the registered vehicles on our roads to be recorded on the Motor e. Local government area where the Vehicle Register. The information helps automobile is been registered enforcement and deters vehicle theft.
Automobile Model you want to use the vehicle on the road again, it h.
Distributed Database Architecture
Automobile Type must be re-registered. Common reasons for i. Color of automobile cancelling registration include vehicles being j. Chassis number 'written off' by insurance companies, destroyed, k. Engine number or rendered permanently useless or permanently l. Number of Cylinders of the automobile removed from Nigerian roads. Engine Capacity process involves a safety inspection, certification, n.
Purpose for which the automobile is been registration, and licensing. The owner needs to registered provide proof that the vehicle has previously been o. Road certificate number q. Testing authority The owner proceeds to make online payment r. Previous Registration number from the designated agent.
On payment, a s. License Office certificate of payment detail of payment is sent t. Owner Name electronically to the vehicles owner record in the u. Owner Status database with the VIO, is issued to the payer. Owner Address owner then proceeds to the Federal Road Safety w.
Distributed Databases and Client-Server Architectures
Commission to collect the necessary vehicle licensing documents and the plate number. A careful study and analysis of the above data Figure 2 presents the physical flow of the systems suggests that while the three governmental arms functionality. Data collection is quite laborious since record keeping is associated with manual data processing. In this research, an attempt was made to formulate a standard operational procedure for the three sectors involved in automobile registration so as to bring effectiveness and reduce duplication of information involved in managing automobile registrations.
Moreover, a centrally managed database and a neural network solution are presented with an element of multi-level data access. One reason vehicles need to be the relation schema R A1, A2. Thereafter, a certificate of is an element of dom Ai or is a special null roadworthiness is issued for the vehicle. The ith value in tuple t, which corresponds to the attribute Ai, is referred to as t[Ai].
A server is a dedicated computer that organization or remotely. The following is list of allows other computers to connect to it. Various the information technology IT infrastructure types of servers exist which include the following: In networking, a workstation connected to the Internet, especially intranets.
All refers to any computer connected to a local area messages entering or leaving the intranet pass network. It could be a workstation or a personal through the firewall, which examines each computer. There are several types Intrusion Detection Systems: Intrusion detection of firewall techniques: Looks at each packet entering computer policy. Applies security systems used in areas with poor over-the-air mechanisms to specific applications, such television reception. This is very effective but can and the signal was then piped to the subscribers' impose performance degradation.
Figure 3 describes the structure of this framework. The Pacific Journal of Science and Technology —— http: November Fall Figure 3: Vehicles must be registered in and fictitious registration. The system is capable order to be used on the public roads and only of generating reports for decision makers to require re-registration if the registration has been enable monitoring.
Vehicle licensing is the payment of a fee for the use of a motor vehicle on public roads. This license label must be displayed on the vehicle. Addison-Wesley In this research, an attempt is made to design a Publishing Company: The system Distributed System Architecture. Morgan consists of a relational database of automobile Kaufmann Publishers: Teturo Sawada, Exclusive Revenue.
Each of these organizations is Publisher and Distributor. Database Managenment Systems, Second Edition. McGraw- The client-server architecture is used as a Hill: The essential decision variables were identified. VIO while the concept of data replication and http: He obtained his B. Maths degree inM. Database System for Licensing and registration of degree in computer science inand Ph. Pacific Journal of Degree in computer science in from the Science and Technology.
Federal University of Technology, Akure, Nigeria. He has since been teaching courses and researching in the areas of information system, databases, expert systems, image processing, software engineering, data mining, advance micro-computing, probability theory, and e-commerce. Olabode has great aptitude for programming and solving numerical problems, particularly those that are related to industry.
He has numerous journal publications and conference proceedings to his credit. He has served as a technical resource expert in many workshops organized for Local Governments in Ondo State. A distributed database application cannot expect an Oracle7 database to understand the SQL extensions that are only available with Oracle Database.
Distributed Databases Versus Distributed Processing The terms distributed database and distributed processing are closely related, yet have distinct meanings. There definitions are as follows: Distributed database A set of databases in a distributed system that can appear to applications as a single data source. Distributed processing The operations that occurs when an application distributes its tasks among different computers in a network.
For example, a database application typically distributes front-end presentation tasks to client computers and allows a back-end database server to manage shared access to a database. Distributed database systems employ a distributed processing architecture. For example, an Oracle Database server acts as a client when it requests data that another Oracle Database server manages.
Distributed Databases Versus Replicated Databases The terms distributed database system and database replication are related, yet distinct. In a pure that is, not replicated distributed database, the system manages a single copy of all data and supporting database objects.
Typically, distributed database applications use distributed transactions to access both local and remote data and modify the global database in real-time. This book discusses only pure distributed databases. The term replication refers to the operation of copying and maintaining database objects in multiple databases belonging to a distributed system. While replication relies on distributed database technology, database replication offers applications benefits that are not possible within a pure distributed database environment.
Most commonly, replication is used to improve local database performance and protect the availability of applications because alternate data access options exist. For example, an application may normally access a local database rather than a remote server to minimize network traffic and achieve maximum performance.
Furthermore, the application can continue to function if the local server experiences a failure, but other servers with replicated data remain accessible. Oracle Database Advanced Replication for more information about Oracle Database replication features Oracle Streams Concepts and Administration for information about Oracle Streams, another method of sharing information between databases Heterogeneous Distributed Database Systems In a heterogeneous distributed database system, at least one of the databases is a non-Oracle Database system.
To the application, the heterogeneous distributed database system appears as a single, local, Oracle Database. The local Oracle Database server hides the distribution and heterogeneity of the data.
If you access the non-Oracle Database data store using an Oracle Transparent Gateway, then the agent is a system-specific application. For example, if you include a Sybase database in an Oracle Database distributed system, then you must obtain a Sybase-specific transparent gateway so that the Oracle Database in the system can communicate with it. Other than the introductory material presented in this chapter, this book does not discuss Oracle Heterogeneous Services.
Heterogeneous Services Heterogeneous Services HS is an integrated component within the Oracle Database server and the enabling technology for the current suite of Oracle Transparent Gateway products.