Topic database features

The basic features of topic databases include:
1. For business topics (not for document reports ). Topic databases are data organization and storage oriented to business topics. For example, the typical topic databases to be created in an enterprise include: products, customers, parts, suppliers, ordering, employees, documents and materials, engineering specifications, etc. The structure of databases, such as products, customers, and parts, is designed to analyze and sort the data items of relevant documents and reports, rather than based on the original documents and reports. These topic databases are associated with the main problems to be solved in enterprise management, rather than with common computer application projects.
2. Information sharing (not private or owned by the Department ). Topic database is a complete denial of the database of each application system "self-built and used", emphasizing the establishment of a shared database for the "joint construction and sharing" of each application system. Computer programs in different application systems call these topic databases, such as inventory management call products, parts, and ordering databases, and purchasing call parts, suppliers, and engineering standard databases.
3. One input system at a time (not multiple input systems ). Topic databases require investigation and analysis of data sources at various business management levels, emphasizing local data collection, local processing, use and storage, as well as necessary transmission, summary, and centralized storage. The same data must enter the system at one time and at one place to ensure its accuracy, timeliness and integrity. It can be used multiple times and in multiple places through the network-computer-database system.
4. It consists of basic tables. The scientific data structure of a topic database is composed of multiple data entities that conform to the "base table" Specification. These basic tables have the following features:
· Atomicity -- the data items in the basic table are data
Elements (minimum information that cannot be further decomposed)
Unit );
· Atomicity -- can be generated from data in the basic table.
All output data (these basic tables are refined
Can generate all enterprises after computing
Manage the required data );
· Normalization-data in the basic table meets the three paradigm
(3-nf) requirements: This is a scientific data structure that can meet the adequacy requirements and ensure quick access.

 

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Topic Database concept

The topic database is designed to accelerate the development of application projects. Data used by programmers should already exist in the relevant database. It divides all the data of an enterprise into theme databases, which can be managed. The theme database should be designed as stable as possible to provide stable services for the enterprise's information resources for a long period of time. Stability does not limit that the theme database will never change, but requires that the changes do not affect the work of existing application projects. The logical structure of the topic database should be independent from the Force implementation process of the current computer hardware and software, so that the logic structure of the topic database is still valid even as the technology keeps improving.

5.4.2 topic database selection

In most cases, there is no formal method for selecting and determining the topic database content. In the implementation process, there is often a lot of debate on a topic database and other issues. James Martin recommends two methods to select and determine the topic database.

First, list the components of the products and institutions involved by the enterprise, such as products, equipment, raw materials, buildings, parts, cash, suppliers, accounts, customers, and shareholders. Each item can have basic records, special records, transaction processing, summary or statistics, plan or design data.

Secondly, you can examine the business activity process and record the data category of the input and output data of each process to obtain a data classification table.

5.4.3 combination of topic Databases

James Martin pointed out that the topic database and the data class in the BSP method are equivalent concepts. When many theme databases and business activities are given, these theme databases must be combined or divided into several sub-systems when implementing enterprise information systems.

5.4.4 4 Data Environments

James Martin clearly distinguishes the four types of Data Environments of computers, and points out that an efficient and efficient enterprise should basically have three or four types of data environments as the basis. The following lists four types of data environments.

1. File Environment

Do not use the database management system. When creating an application project, the system analyst or program originally designed some independent data files. For most application projects, such independent files are used.

2. Application database environment

When a database management system is used, its data sharing level is higher than that in the file environment but lower than that in the topic database environment. Each Independent database is designed for each independent application project.

3. Topic database environment

Database creation is basically independent of specific applications, and data design and storage are independent of their application functions. The relationship between data related to business topics is represented by a shared database.

4. Information Retrieval System Environment

This category is designed for automatic information retrieval, decision support systems, and office automation, rather than dedicated computing and a large amount of productive data. New data can be dynamically added to the database. The software is designed around this inverted label and other data retrieval technologies, providing a good end user language, you can use these languages to flexibly create your own logical data files.