The basic steps and requirements are as follows:
1 Requirements Analysis Step (commonly used from top to bottom)
The first. The database design stage involves accurately understanding and analyzing user requirements (including data and processing). Requirements analysis forms the foundation of the entire design process and is also the most difficult and time-consuming step. Whether the requirements analysis is sufficient and accurate determines the speed and quality of creating a database based on it. If the needs analysis is not done well, the entire database design will be redone.
The task of requirements analysis is to fully understand the operating profile of the original system through a detailed investigation of the objects to be processed in the real world, to clarify the different needs of usersators, then determine new functions of the system. and new system functions based on this. Possible extensions and modifications in the future must also be fully taken into account, and the design cannot only be based on current application requirements. The investigation focuses on data and processing.
The analysis method to meet information, processing, security and integrity requirements is the commonly used SA (Structured Analysis) method. The SA method starts from the top-level system organizational structure, using the top level. -down, Analyze the system layer by layer.
2. Conceptual structure design stage (commonly used from bottom to top)
Conceptual structure design is the key to the entire database design. It forms a basiscomplete data by synthesizing, summarizing and abstracting. user needs. A conceptual model independent of a specific DBMS.
3. Logical structure design stage (E-R diagram)
Logical structure design involves converting the conceptual structure into a data model supported by a certain DBMS and optimizing it.
4. Physical design stage
Physical design is to select a physical structure (including storage structure and access method) most suitable for the application environment for the structure model of data logic< /p>
method).
5. Database Implementation Phase
In the database implementation phase, designers leverage the database language (such as SQL) and its provided host language by the DBMS, and design according to the logic.
Create a database with the results ofphysical design, compile and debug applications, organize data in the database, and perform testing.
6. Database operation and maintenance stage
After the trial operation, the database application system can be put into formal operation. During the operation of the database system, it must be tested continuously.
Evaluate, adjust, modify.