Database design Process

Database design process At present, the database design is generally divided into 6 stages,

That is, demand analysis stage, conceptual structure design stage, logical structure design stage, physical structure design stage, implementation stage, operation and maintenance stage.

(1) phase of demand analysis

The main task of the requirement analysis phase is to understand the working condition of the computer system, clarify the various needs of the users, and then determine the functions of the system by fully investigating the objects to be dealt with in the real world. The database system should not only be designed according to the current application requirements, but also must consider the possible future expansion and change.

(2) conceptual structure design phase

The main task of the conceptual structure design phase is to abstract the user requirements from the requirement analysis stage into a conceptual model, and the specific tools to describe the conceptual model are mainly E-R models.

(3) logical Structure design phase

The main task of the logical structure design phase is to transform the basic E-r model of conceptual structure design stage into a logical structure conforming to the data model supported by the DBMS product. Specifically, it is the first transformation of the conceptual structure into a general relational, mesh, hierarchical model, then transforms the transformed model into a data model supported by a particular DBMS, and finally optimizes the data model.

(4) Physical Structure design phase

The main task of the physical structure design phase is to select a physical structure that meets the application requirements for a specified logical data model. Specifically, it is first to determine the physical structure of the database, that is, the database access methods and storage structure; The physical structure of the database is then evaluated, and the emphasis is on the length of the access time and the size of the storage space.

(5) implementation Phase

The main task of the implementation phase is to use the data definition language and other utilities provided by the RDBMS to describe the logical structure design and the results of the physical structure design in detail to become the source code acceptable to the DBMS; Then through the system debugging to generate the target mode, the final completion of data loading work.

(6) operation and Maintenance phase

Key tasks in the run and maintenance phase include database dumps and restores, database integrity and security controls, database performance transformation, analysis and oversight, database reconfiguration and re-organization