3. Database design
1. Performance requirements for database platform
Establish a perfect database structure to manage the basic parameters, operation status and various work plans of the equipment. The framework and structure of the database must be designed according to the equipment and operation status to facilitate the provision of powerful input, query, statistics, analysis and report functions, better reflect the basic situation and operation status of the platform business, and meet the requirements of operation management informatization.
According to the characteristics of the system data, we use MySQL as the database platform of the system, and standard SQL statements are used in database development for future expansion and transplantation.
The system will use database modeling tools to build the entire database according to the design of system functional modules. When building a database, the constraints, associations, and indexes of database tables will also be defined.
According to the specific characteristics and system requirements of the system, we put forward the following performance requirements for the database platform when designing the database scheme:
High degree of standardization, in line with the standard ANSI SQL 92 language specification;
Support Brower/SERVER mode applications, support symmetric processing and multithreading technology, support XML/CORBA, and support data partitioning;
It can run under multiple operating systems, HP, IBM and other servers, with strong independence and little impact on the system structure;
Advanced language and Chinese language features, easy to use, support Chinese characters, GB18030 standard;
Support various mainstream network protocols, such as TCP/IP, IPX/SPX, NETBIOS, DECNET, SNA, etc.
It can support distributed operations of homogeneous and heterogeneous networks, loosely coupled clusters and massive parallel processing;
Sufficient concurrency control; Authorization control and transaction processing capability and recovery capability;
Good interoperability with heterogeneous data sources;
Have reliable data security measures and fault recovery capability;
It has SMP and MPP functions, fast concurrent user query speed, and stable and reliable concurrency control;
It has strong fault tolerance, error recovery, error recording and early warning capabilities, as well as remote disaster tolerance;
It allows row level locks, and has the function of automatically unlocking deadlocks without additional data consistency verification;
It has strong replication capability, supports master-slave, cascade, pair and N-direction replication, and supports replication log technology, with distributed mode management capability;
It has complete security (account security, system level permissions, object security, audit), fine-grained access control, and the ability to adapt to the security model of a multi-layer environment;
It has powerful development tools that support MIS, and provides data warehouse and data mining tools.
2. Structure design of database system
According to the structure and application services of the system, and taking into account the integration scheme, function expansion and flexibility of the whole system, the database will adopt an architecture combining centralized mode and three-tier structure according to the following principles.
This system is a service platform system, which can provide standard application services. These services can be run in a centralized manner to make full use of server resources, give play to server performance, facilitate management, and improve reliability.
It is easy to expand the client by using the three-tier structure. Using multiple servers can reduce the system's processing bottleneck, improve the system's performance, and share all resource database systems in the network, providing a reliable technical guarantee for the application of centralized mode and B/S structure.
3. Logical structure of database system
Considering the overall requirements of the system and the future development of various businesses, the logical structure of the database system designed in this scheme reflects the following characteristics:
The database system structure has good compatibility.
Comprehensiveness of database data: investigate, analyze and require image data, user data, text information, etc., to maximize their data sharing, while reserving data interfaces for system scalability, so as to achieve the goal of data comprehensiveness.
The database system structure is completely complete: it can not only maximize public data, but also strictly confidential transaction settlement data and enterprise private data. Different security management mechanisms should be used for different types. The information system will adopt a large database system, complete data backup and security control strategy, to ensure the security and integrity of data and ensure the safe operation of the system. The database can adopt data redundancy backup, or data video backup and dual computer backup to ensure the safety and integrity of data.
4. The database design follows the technical specifications and standards
Purpose: to ensure seamless connection with other application systems, and facilitate data sharing with other systems of the operator and data sharing of social resources of all parties in the park.
(1) Perfect coding system
Perfect coding system is one of the important cores of database system. It is required to comprehensively classify and code the information covered in the business.
The coding design is required to be scientific and reasonable, so that the system can have the advantages of directory tree structure display, clear classification path, multi-level synchronous maintenance (cascade modification), multi-level query of classification and classification, and less data transmission.
(2) Dictionary driven database structure
The development and changes of the system correspond to the increase and decrease of equipment (entity object) attributes and equipment (entity object). The expansion and modification of equipment attributes and the definition of new equipment can be realized in the database by means of data dictionary drive.
The system adopts this dictionary driven database structure, through which users can expand the attributes of an object in the system as required. For example, when applied to equipment management, graphical interfaces can be used to simply and intuitively realize the customization of equipment types, increase of equipment types, and customization of equipment attributes, so as to meet the needs of emerging new equipment without modifying the program code.
(3) Object-oriented database design
In a sense, it is the object-oriented characteristics of database design that ultimately establish the object-oriented nature of the whole system. Specific requirements include:
The database structure is clear and easy to implement OOP
Database objects are independent and easy to maintain
When requirements change, the program and database have high reuse rate and few modifications
(4) Flexible expansion technology
The database system endows the query system with high flexibility and sufficient scalability. The query system can constantly improve itself according to the needs of users to provide new query functions and enhance query capabilities. It has two meanings: first, after the system has been running for a period of time, users are likely to have new query requirements. On the basis of good data structure, users can meet their new requirements by properly adjusting and configuring the original system; Second, the application system has the function of providing various customized queries for different types of users, reducing the maintenance workload and cost of the system in the later period, and protecting the early investment of the system.
(5) Management of unstructured data
The system adopts a reasonable database management mode for unstructured data such as documents, manuals, reports, opinions, etc.
The system brings unstructured data into the database system for management, thus integrating enterprise data sources and applications into an organic whole, realizing centralized management, organization, classification, indexing and retrieval of data, so as to achieve efficient operation of structured data such as numbers and characters and unstructured data such as electronic documents, images and sounds.
(6) Process data storage management
The data generated in the whole process of a business process from the beginning, middle stages to the end and feedback is stored in a complete association, which not only completes closed-loop management on the business process, but also completes closed-loop management on the data generated by a specific work, and finally realizes the function of closed-loop management and monitoring in the true sense of the business.
The simplest is the best
The objective world is complicated, and the development of computer science theory is more and more profound and complex. However, the ultimate goal of human exploration of theory and technology is to make the complexity of the objective world simple, and the simplest is the best. Therefore, the following requirements are proposed for database design:
Use foreign keys carefully
Appropriate redundancy
Information concealment
(7) Backup management
Realize the backup of all data of the system, including graphic data, attribute data and rule base data, which are stored in the database and backed up regularly to ensure data security.
