УДК 004.9

МЕТОД НИСХОДЯЩЕГО ПРОЕКТИРОВАНИЯ

Кувайцев Александр Вячеславович
Димитровградский инженерно-технологический институт филиал национального исследовательского ядерного университета «МИФИ»
студент

Аннотация
В данной статье описывается метод нисходящего проектирования. Нисходящее проектирование – это проектирование сверху вниз, и характеризуется противоположной последовательностью выполнения процедур. Методика нисходящей, или пошаговой разработки программ считается самой сильной формализацией в области проектирования алгоритмов начиная с 70-х годов.

Ключевые слова: нисходящее проектирование, проектирование, разработка


TOP-DOWN DATABASE IMPLEMENTATION

Kuvaytsev Aleksandr Vyacheslavovich
Dimitrovgrad Engineering and Technological Institute of the National Research Nuclear University MEPHI
student

Abstract
This article describes the top-down approach. Top down design is a top – down design, and is characterized by the opposite sequence of treatments. The technique of cascading or step-by-step of program development is considered the most powerful formalization in the design of algorithms since the 70-s.

Keywords: Top down design, top-down approach, top-down database implementation


Рубрика: 05.00.00 ТЕХНИЧЕСКИЕ НАУКИ

Библиографическая ссылка на статью:
Кувайцев А.В. Top-down database implementation // Современные научные исследования и инновации. 2016. № 11 [Электронный ресурс]. URL: http://web.snauka.ru/issues/2016/11/74371 (дата обращения: 30.04.2017).

At the “downstream” design structural design is carried out from top to bottom. Such a design is called analysis – there is a whole study (description of the subject area), then the division of the whole into its component parts and then be consistent study of these parts[1].
Stages of database design method of “top-down” design shown in Figure 1.

 Figure 1 – Steps of designing a database by ” top-down ” design

To display method uses the following symbols: circles described in the names of the stages of design, in rectangles – results[1-3]. Design begins with an analysis of the subject area and describe the formation of an external database level, which brings together represent all users to develop database to identify classes of objects (entities) subject area, links between them. On the basis of the description of the external level conceptual information is based logical domain model (BLM), and then based on it get datalohic model (DLM) database. DLM is the basis for the next stage of the design database – phase formation of the physical database model. Such an approach to the design of the database is also called a conceptual or conceptual design.
The conceptual approach to the design of the database are the following three areas:
-Real world or object system;
-Information sphere;
-Datalohic sphere.
The main components of the system are the object: the object (entity instance), property (attribute), the ratio of (communication) (defined subject area, if known existing objects, their properties and relationships between them)
The object in the conceptual approach – this is what the information system should collect information.
Objects grouped into classes of objects (instances of entities in nature, or they say – the type of entity). An object class may consist of one or more objects. For example, the object class individual, the individual objects – Ivanov, Petrov, Sidorov.
Each object class must have a unique identifier that uniquely identifies each individual object (entity instance) in the class of objects[4]. Each object class should have some properties (attributes), the number of which is the same for each object in the object class, the value of each property can be different in different sites. Each feature class can have any number of links with other classes of objects.

Based on top-down approach is the idea of establishing a consistent matching between object system, information and further datalohic areas. Is a sequential transformation of understanding of domain objects and relations between them in a formal description logic information of the subject area and further conversion of the logic information of the subject area the description of the structure of the database in terms of selected data structures – construction logic and data. This gradual transformation allows a clear and simple manner to realize correct displaying of the sense of the real world in a database.


References
  1. Designing. [Электронный ресурс]. URL: https://ru.wikipedia.org/wiki/ Проектирование (дата обращения 09.11.2016).
  2. The upward and downward software design. [Электронный ресурс]. URL: http://tehprog.ru/index.php_page%3Dlecture32.html (дата обращения 09.11.2016).
  3. Structural design and programming. [Электронный ресурс]. URL: http://any-book.org/download/80386.html (дата обращения 09.11.2016).
  4. Descending and ascending design. [Электронный ресурс]. URL: http://life-prog.ru/1_36016_nishodyashchee-i-voshodyashchee-proektirovanie.html (дата обращения 09.11.2016).


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