Chapter 1_Development method of database application system
test analysis
◆Generally, it will appear in multiple-choice questions and fill-in-the-blank questions in the exam.
◆Common test knowledge points include:
1. Master the life cycle of database application system and DBAS life cycle model
2. Master the content of system planning and definition
3. Master the demand analysis of data, function and performance
4. Understand concepts, logic and physical
design5 .Familiar with implementation and deployment
1.1 Database application system life cycle
1. Basic concepts
1. Database system (DBS)
2. Mainly provide data management functions such as organization, storage, maintenance, and access of application data.
Database application system (DBAS)
a. Provide users with data management functions,
b. According to specific applications Domain business rules implement more complex data processing functions through applications.
Note:
DB: database
DBMS: database management system
DBA: database administrator
2. Software engineering and software development methods
1. Software engineering thinking: use engineering concepts, principles, technologies and methods to track and manage the whole process of software production and development.
2. The purpose of software engineering development: to improve the quality of software, accelerate the speed of software development, and reduce costs.
3. Typical software development models: waterfall model (software life cycle model, software process model), rapid prototyping model, spiral model, etc.
(1) Six stages of waterfall model
1. Project planning
2. System analysis
3. Overall design
4. Detailed design
5. Coding debugging and integration debugging
6. Operation and maintenance
Advantages: ensure system consistency and completeness Disadvantages
: users cannot be discovered Potential demand
(2) Rapid Prototyping Model
1. Rapid Analysis
2. Design and Construction Prototype
3. Run Prototype
4. Evaluate Prototype
5. Improve Prototype
(3) Spiral model
1. Project planning
2. Risk assessment
3. Engineering realization
4. User assessment
(for the next cycle)
3. Database application system (DBAS) life cycle model
1. Project planning (system planning and definition {determined view}, feasibility analysis {economic, operational, technical, development plan feasibility}, project planning) 2. Demand analysis
(DBAS
3. System Design (
1) Conceptual Design
(2) Logical Design
(3) Physical Design
4. Implementation and Deployment
5. Operation and Maintenance
1.2 Planning and Analysis
1. System planning and definition
For the DBAS to be developed, by understanding the actual needs of users, clarify the goals and tasks that the system needs to achieve, and determine the functions and performance ranges of the database software in the system from the perspective of data management and data processing.
1. System planning and definition
(1) Mission statement: describe the overall goal of the DBAS to be developed.
(2) Determination of task objectives: To clarify the overall objectives of the system, a series of data management and data processing tasks and activities that DBAS should support.
(3) Determine the scope and boundaries: define what DBAS does, what it doesn't do, and to what extent.
(4) Determining the user view: Classify users, clarify which data in the database each type of user needs to access and how to use these data, and form the user view corresponding to the user.
2. Feasibility analysis
1. Economic feasibility
System software and hardware purchase cost, system development cost, system installation, operation, maintenance cost, etc.
2. Technical feasibility
Hardware feasibility, software feasibility, and technical solution selection
3. Operational feasibility
demonstration whether DBAS development is available All kinds of human resources, software resources, hardware resources and working environment required.
4. Development plan selection
3. Project planning
1. Determine the goal and scope of the project, and specify the final product of the project and the expected time, cost, and quality goals according to the work content of the system planning and definition.
2. According to the DBAS software development model, decompose and define the work activities and tasks included in the entire project.
3. Estimate the scale and resources needed to complete the project.
4. Formulate a reasonable DBAS project plan, including forecast and control schemes in terms of schedule, cost, and quality.
1.3 Demand Analysis
1. Data requirements analysis
1. Definition: From the perspective of organizing and storing data, and starting from the user view, analyze and identify various data items and data structures managed in the application field to form the main content of the data dictionary.
2. The data dictionary consists of five parts: data items, data structure, data flow, data storage and processing.
2. Functional requirements analysis
1. Concept: It mainly analyzes the functions that DBAS should have, which is the core link of DBAS requirements analysis.
2. Classification
(1) Analysis of data processing requirements through data flow diagram (DFD): form a data dictionary document
(2) Analysis of business rule requirements (UML diagram).
3. Analysis of performance requirements:
response time, system throughput (TPS), maximum number of users allowed to access concurrently, and value per TPS.
4. Analysis of other requirements
1. Analysis of storage requirements
(1) Database size
(2) Growth rate of database storage
2. Analysis of security requirements
3. Analysis of backup and recovery requirements
1.4 System Design
1. Concept: If the task of the requirements analysis phase is to solve the problem of "what to do", then the task of the system design phase is to determine "how to do it".
2. Conceptual design (ER diagram)
1. Database concept model design
2. System overall design
DBAS architecture design, hardware platform selection and configuration, application software structure design, preliminary design of business rules, selection and analysis of key technologies Preliminary design
3. Logical design (relational model)
1. Database logical structure design
2. Application program outline design
3. Database transaction outline design
4. Physical design
1. Database physical structure design
2. Database transaction detailed design
3. Application program detailed design
1.5 Implementation and deployment
Building database structures, data loading, coding and testing of transactions and applications, system integration, testing and commissioning, system deployment
1.6 Operation Management and Maintenance
1. The operation management of the database application system and the operation management of the database itself. The DBA is in charge.
2. DBAS operation management and maintenance
1. Routine maintenance
Backup and recovery, integrity maintenance, security maintenance, storage space management, concurrency control
2. Monitoring and analysis
Data collection and statistics, operation analysis, benchmark program evaluation,
3. Performance optimization Adjustment
Query adjustment and optimization, index adjustment, transaction adjustment, mode adjustment, parameter adjustment, hardware adjustment and upgrade, application optimization 4. System
evolution
Application upgrade, database reorganization, DBMS and OS upgrade