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Abstract
theme: "Development of algorithms of data organization of the client-server systems"
Author: Reznichenko V.L. |
Introduction
It is known that the informative systems based on architecture client-server can possess substantial advantages as compared to the informative systems based on the network versions of table SÑD( System Control Database). Among advantages it is possible to select a high performance, low network traffic, built-in facilities of providing of safety and data integrity, possibility of storage of business-rules in a database and the uses of them at creation of client appendixes. The using of all these advantages can be effective, at first, at the correct planning of information, and, secondly, at the observance of rules of optimization of both server and client parts of the informative system.
Urgency of a theme
The problem of designing of data has the general character and has no direct attitude to a choice of the tool of development . The using of modern facilities of planning of databases, and, in particular, CASE-technologies, substantially facilitates the decision of this problem, but not at all removes her. The reason of it consists that the informative systems are created by programmers which are experts in programming, and quite not in that subject domain, which the informative system is created for. Co-operation of programmer with a customer quite often is complicated by the terminology mutual ununderstanding. For this reason it is necessary to simplify the process of creation of similar applications. It is necessary to create an algorithm which step-by-step minimizes the expenses of resources of developers in organization of business-logic of application and data storaging.
Purposes and tasks
Development of algorithms of data organization of the client-server systems is the purpose of this work. For achievement of the given purpose solve such problems:
1.
Studying
of already existent algorithms of creation of the client- server systems.
2. The analysis of existent algorithms and choice from them optimum.
3. Creation of test application on the basis of the chosen algorithm.
In a role of test model the multiuser application of the account of attendance and students progress is used. The test application uses a database, which contains information about every student, curriculum of every group and amount of the visited and skipped lectures.
The basic purpose is the finding of the decision which will allow coming to system of the objects, capable to simplify perception of a concrete challenge. Basic advantage of objective paradigm just and consists of facilitation of understanding of the tangled logic. It is necessary to develop good model of a subject domain for real business. It is very difficult problem, but its decision brings, good result.
For designing of project the IBM Rational Rose 2003 environment and universal modeling language UML was used. The test application was developed in programming language JAVA and technology Microsoft SQL Server. For development and testing the NetBeans IDE 6.0.1 environment was used.
Scientific novelty
The scientific novelty of this project consists in systematization of creation of client-server applications and organization of data storage. Accordingly it is necessary to speak about logic designing as about the description of characteristics of sets of objects, data about which will collect, and to be used in information system, and about the physical designing representing the description of tables, indexes, and also triggers.
Description of results
The test application must provide simultaneous work of a few users with a database. The application supports the control of versions of information, that provides permanent actuality of information, contained in a database. Access to the base is possible only for two types of users. It is the administrator and the teacher. Both users have the sanction to work with a base only after entering of the unique password. Functions executable by an administrator and teacher are different, but also is present and general. For example, registration of students, groups and curriculum on a semester enters in the function of administrator. The conduct of account on visited and progress of students enters in the function of teacher. A database is on a server, and client part can be set on the personal computer of every teacher. Only due to that this application is multi-user, work can be conducted by a few teachers simultaneously.
Fig. 1 Interaction of the client with a database (8 frames x 0.5 sec. 4 seconds animation, amount of repetitions - 3)
Conclusions
For the planning application model decisions of presentation of business-logic, objective-relational model decisions, intended for the design of conduct, model decisions of objective-relational reflection with the using of metadatas were considered. On the basis of the considered algorithms the methods of planning and realization of appendix were developed.
Sources
1. David M. Kroenke "Database processing", 8-th edition, Kharkov 2003.
2. M. Fauler "Corporate programm applications architecture", Moscow 2006.
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