Three phases of data management development

Data Processing refers to the sum of a series of activities that collect, organize, process, store, extract and disseminate various forms of data.
Data management refers to the organization, storage, retrieval, and maintenance of data, and is the central part of data processing. This service improves data independence, reduces data redundancy, improves data sharing, and improves data security and integrity so that users can effectively manage and use data resources.
1. manual management stage:
2. File Management stage:
3. Database System Management stage
Since the late 1960s S, the application field's requirements for computer and data management have increased, and computer hardware and software have also developed. These are:
● As computer applications increase, the amount of data managed increases dramatically;
● Strong requirements on data sharing and data redundancy reduction;
● The development of hardware involves large-capacity disks;
● The requirement for real-time connection processing increases;
Computer technology is used for data management. It refers to the use of computer software and hardware to store, inspect, maintain, and perform various operations and operations on data. Data management using computers is divided into three phases: manual management, file system management, and database system management.

1. manual management stage:

In the early days of the emergence of computers, they were mainly used for scientific computing without large storage devices. People send programs and data to be computed to a computer through punched tapes. The computing results are manually saved by users. The processing method can only be batch processing, data is not shared, and data cannot be exchanged between different programs.
The data used in applications must be defined by the programmer for the data storage structure and access method. A group of data can only be oriented to one application, and cannot share data with multiple programs. Different programs cannot directly exchange data, and the data is not independent.
● Data is manually saved
● A group of data can only be oriented to one application, and data cannot be shared among multiple applications.
● Different programs cannot directly exchange data without any independence.

Object-Oriented Programming Language

1. First Generation: hierarchical and mesh databases:

(1) Hierarchical Database System:
The Database Management System (IMS --- Information Management System) developed by IBM in 1968 allows multiple COBOL programs to share the database. The system is designed for programmers, the operation is difficult. However, due to the strong competitiveness of IBM products, IMS has become a well-known database system and has been widely used.
Level database IMS is the first DBMS system in the world. It uses a level data model and can only process the relationship between and data.

(2) mesh Database System:
In October 1969, dbtg (Data Base Task Group database task group), a subsidiary organization of codasyl (Conference on Data System Language Association), proposed a database system for the mesh model. The organization clarified many database concepts in a series of database work and reports, laying the foundation for database maturity. The dbtg report specifies all the terms and specifications of the mesh database. The mesh database system provides:
· Data Description Language (DDL)
· Data manipulation language (DML)
The network database system is based on the codasyl dbtg report in the United States. The mesh model can describe the relationship between data in the Real World:, 1: N, and M: n (many-to-many. However, it is not convenient to convert many-to-many relationships.

2. Second Generation: relational database system (RDBMS)

E. f. code published a paper on "Data Relationship Models of large shared databases", put forward the concept of a relational database model, and laid the theoretical foundation for the relational database data model, database technology has become an important branch of computer science and has created a research on the relational methods and standardization of databases. Due to the perfection in theory and simplicity in structure, relational methods play a key role in the development of database technology. Since then, some relational database systems have emerged. In 1974, the San Joe Research Institute of IBM successfully developed the relational database management system (system R. In 1984, the book "relational database theory" by David marer marks the maturity of relational database theory.
1980s was the heyday of the Development of relational databases, and it has been a long time. It has the following advantages:
· Non-procedural database language SQL is used;
· It has a good formal theoretical basis and a high degree of data independence;
· Easy to use. 2d tables can directly process many-to-many relationships.
Currently, RDBMS that are widely used in China include Oracle, SQL Server, Informix, DB2, and Sybase.

 

Due to many advantages of relational databases, such as the good formal foundation, high data independence, non-procedural database language, and the convenient use of two-dimensional Relational Tables, you can directly process, 1: the relationship between N and M: n (many-to-many) makes relational databases still widely used in the 21st century.
Programming languages are classified into procedural and non-procedural languages. The so-called procedural language refers to the question of "what to do". You must specify how to do it to complete your command. For example, the programming languages we have learned: C and Pascal are both procedural languages. During programming in these languages, to print a piece of data, you must specify how to find the data, that is, specify its storage location or variable. Rather than procedural languages, the system can automatically complete your tasks by proposing "what to do" and not specifying how to do it. Relational Database language SQL is a non-procedural language.

3. Third Generation: Object-Oriented Database System oodbms (Object Oriented DBMS)

With the development of computer technology, the field of computer application is constantly expanding, from scientific computing to enterprise resource management, to engineering design, such as computer aided design CAD, computer aided manufacturing cam, multimedia applications, artificial intelligence and other fields. These new fields have put forward many non-traditional application requirements for database technology:
· Store and manage a large number of complex data and entities, such as multimedia data, graphic and image data, hypertext data, spatial data, and temporal data. These complex data types are not fully supported by relational databases.
· Retain the design history and version data. In the engineering design process, a design component has multiple design stages, and each design stage has multiple different design schemes. Each design scheme can have different design revisions. To support repetitive and tentative design in the engineering design process, multiple versions of each design object must be retained.
· Stores a large amount of standard parts and engineering data. Stores a large amount of standard data of national standards or local standards, as well as engineering design requirements and specifications.
· As the engineering design progresses, the model structure of the design object also changes, and the data model must be dynamically modified.

With the requirements of new application fields, in the late 1980s s, an object-oriented database management system (oodbms) that supports object-oriented data models emerged. Commercialized oodbms, such as ObjectStore, Ontos, Versant, and gemstore.

1. Object Relational Database Service (ordbms)

Ordbms is generated by expanding complex data types and Operations Based on relational model databases. The main expansion includes adding object classes for describing non-text and unstructured data and supporting functions for corresponding object operations, so that the database system can meet the needs of cross-platform and different media objects, in particular, it supports Web database applications.
The extension of Object Relational Database Service supports SQL language, so it is relational and supports complex data types, so it is object-oriented. In essence, it is the combination of SQL in the relational world and the model primitive in the object world. It maintains all the functions and advantages of RDBMS and adds flexible functions to the database server, supports complex "user-defined" application objects.
As mentioned above, traditional data types and SQL search capabilities are insufficient to meet the database technology requirements of new applications. At the same time, what we need is not the accumulation of a new set of data types and new functions, but a way for users to flexibly define the required data types and functions, the database must not only store multiple data types, but also perform and operate on multiple data types.
In order to allow users to customize data types/functions and behavior rules for user-defined operation data, the following two aspects are extended based on relational databases:
(1) first, add "object architecture" to the relational database management system to support user-defined data types, functions, and rules. For example, define large unstructured objects and define user constraints and triggers.
(2) The second is to establish a "relational extender" based on the object architecture ".
A system that includes both the underlying object structure and a set of relational extenders is called an "Object Relational" database system. The object relational system combines the advantages of object-oriented programming languages with the features of relational databases and advanced non-procedural query languages.
The basic application fields of object-relational database include CAD, Cam, Capp, CAE, and e-commerce. The main content of expansion is the expansion of data types and functions (methods and operators. The method is to combine the advanced query language with multiple views of data to capture more data semantics. Basic Features of Object Relational databases include:
(1) complex objects: Objects composed of multiple basic or user-defined types, such as multimedia data, hypertext data, temporal data, and graphic and image data.
(2) Inheritance: supports class inheritance. When you integrate complex data into a database, you also need to automatically apply business rules to ensure data integrity and consistency.
Take the DB2 relational database of IBM as an example to describe the object architecture of the object relational database and its relational extender.
　　
(1) object architecture of DB2
· User-Defined large objects. DB2 provides three data types for storing large objects: blob for storing large binary objects, clob for storing large string objects, and dbclob for storing double-byte string objects. All three types can store up to 2 GB objects.
· User-defined functions. DB2 provides more than 100 built-in functions to compute numbers, strings, dates, and other types of data, you can use C, C ++, and other languages to create your own new functions. User-defined functions can also contain parameters and can contain SQL statement expressions that obtain scalar values.
· User-defined data types. Based on the built-in data types of DB2, you can create your own data types and specify operations suitable for custom types.
(2) relational extenders
Based on the underlying structure of the object, you can write a relational extender to support applications in specific fields. DB2 provides the following extenders:
· Text extender: supports fast Content-based retrieval of large text documents. It has no specific requirements on the document storage format and is suitable for popular document formats such as Word and TXT. Supports document processing in 18 languages. Using the built-in language knowledge, you can use a special indexing method to index the content of the entire document for quick search.
· Image extender: it can store and retrieve images in several popular formats, including GIF, JPEG, and BMP. You can perform content-based image search. For example, search for images that are similar to the given sample color and structure.
· Video extender: stores and retrieves video sequences in several popular formats, including mpeg1, Avi, and quick-time. It can automatically split a video into "lenses" by detecting scenario changes, and retrieve representative images from each "lens.
· Sound extender: stores and retrieves audio clips in several popular formats, including AIFF, Midi, and wave. It can detect the characteristics of sound data, such as the playback time of a clip, the number of audio tracks, and the number of songs.
· Fingerprint extender: stores and retrieves fingerprints in a specific format, which can search for fingerprints similar to a given sample.

1. All manual programming stages
From the scientific calculation of data to the drawing of engineering drawings, programmers must write programs one by one.
　2. Large professional application packages
The generation of large-scale professional application packages simplifies the programming of engineers. They don't need to write the underlying general programs, and focus on designing how to use various software packages; to implement complex engineering computing and complex engineering design tasks. For example, the Finite Element Library, the mathematical science library, and the Computer Drawing Library. In 1980s, the main plotting procedures were CGI, GKS, phigs, and plot10. Mathematical science computing library, such as matlib
　3. Extensive use of graphic Interaction Technology
· Improved computer performance; the development of graphics input/output devices: high-definition display, mouse, drawing machine, scanner, etc., makes it very intuitive and convenient to use computers for graphics processing.
· Interactive graphics software has developed rapidly, such as the commercial user interface management system (UIMS), ms_windows, x_window, open look, mortify, OpenGL, and other interactive graphics software.
· Intuitive, visual, and flexible interactive graphic interfaces.
With the development of computer hardware and peripheral devices, the computer's performance has improved, and Graphics Input/output devices have developed: for example, high-definition display, mouse, plotter, scanner, etc, this makes it very intuitive and convenient to use computers for graphic processing. Interactive Graphics Software has developed rapidly. In addition to many interactive graphic user interface management systems (UIMS), various graphical controls, Component Libraries, and various programming languages, software Tools and database systems also provide various menus and form designers, making it easy to construct an intuitive and flexible Interactive Graphic environment.
　4. Computer Integrated Manufacturing System CIMS
With the advancement of worldwide science and technology, many new information and knowledge are generated every day in the world around us. This includes technology, science, commerce, geography, and aviation. It forms a powerful ocean of information, so that the amount of information will be doubled every few years. These large amounts of information can only be managed using modern computers and communication technologies.
CIMS is a new and high technology that guides enterprises to plan, create and adjust their business models from a global and systematic perspective, it adopts information technology, automation technology and advanced management technology to complete product design, production, management, operation decision-making, and market services. In the current global market competition, every enterprise is faced with competition for new products with continuously increasing technological content. In the face of fierce competition, the manufacturing technology must be combined with the rapidly developing information technology and automation technology to form a new generation of advanced manufacturing technology ). Make the product from the minimum time to market (T-time to market), the best quality (Q-quality), and the lowest cost (c-cost ), the best service and the cleanest environment meet the customer's requirements for the product. The ideas and methods of CIMS System Integration improve the agility, flexibility, and strong performance of enterprises. It helps enterprises adapt to the development trend of small batches, multiple varieties, fast and sophisticated, and expands the market to increase profits.
Computer Integrated Manufacturing System (CIMS) is proposed to integrate product information (including technical information and management information) into storage and management. Based on automation, network, and manufacturing technologies, CIMS integrates all the business activities of a company, a unit, or a factory through computers and software: all data such as planning, design, production, sales, maintenance, cost accounting, and finance and personnel are organically integrated to establish a comprehensive computer-aided information processing process, to adapt to multi-variety, small batch production of the overall high efficiency, high flexibility of the intelligent manufacturing system.
 

In 1974, Dr. Joseph Harrington proposed the concept of CIM (Computer Integrated Manufacturing) in the book computer integrated manufacturing. The main points are: (1) all production links of an enterprise are inseparable and must be arranged in a unified manner-"System Viewpoint ". (2) The product manufacturing process is essentially the process of information collection, transmission, and processing-"information concept ".
Terms in CIMS:
CAE = Computer Aided Engineering
CAD = Computer Aided Design
Cam = Computer Aided Manufacturing
Capp = Computer Aided Process Planning
MRP = material resource planning
MRPII = Manufacturing Resource Planning
ERP = Enterprise Resource Planning
CAX: a general term for various computer-aided software, including CAD, Cam, CAE, and Capp.