I. The concept and development of file system and database system
1. File system
The so-called file system simply says the software structure that is responsible for accessing and managing file information. For example, the computer's hard disk C, D, E, F, and movable storage devices. A file system is a method and data structure that the operating system uses to clear files on a disk or partition, that is, the method of organizing files on disk. Also refers to the disk or partition that is used to store the file, or the type of file system. The software organization that manages and stores the file information in the operating system is called the file management system, referred to as file system.
The file system consists of three parts: software related to file management, managed files, and the data structures required to implement file management. From a system point of view, the file system is to organize and allocate the file memory space, which is responsible for the file storage and the protection and retrieval of the deposited files. Specifically, it is responsible for creating files for users, depositing, reading, modifying, dumping files, control file access, when the user is no longer used when the revocation of files.
2. Database system
Database system is a system composed of database and database management software, it is a kind of ideal data processing core organization developed to meet the need of data processing. It is a real operational storage, maintenance and application system to provide data software system, is the storage media, processing objects and management system of the collective. The core of database system is database management system.
Database system generally consists of 4 parts: database, hardware, software, personnel.
A database is a collection of organized, shareable data stored in a computer for long periods of time. Hardware refers to the various physical devices that make up a computer system, including the external devices required for storage. The software includes operating system, database management system and application program. People include system analysts and database designers, application programmers, end users, and database administrators.
database system is of the size, the common large database system has SQL Server, Oracle, DB2, etc., Small and medium database systems have FoxPro, access, and so on.
3. Development process
The development phase of the database is broadly divided into the following phases: The artificial management stage, the file system stage, the database system stage, the advanced database stage. The following is a brief introduction to the file System Management phase and the database management phase. The advent of the operating system in the file system phase marks a new era in data management. During the file system phase, the data is stored in external memory, and is managed uniformly by the operating system. The operating system provides a friendly interface for users to use files. The logical structure of the file is decoupled from the physical structure, and the program and data are separated, which makes the data and the program have a certain independence. The user's program and data can be stored on the external storage separately, each application can share a set of data, realize the data sharing in the file unit.
In the database system stage, people have put forward higher requirements for data management technology: They want to organize data with data as center, reduce data redundancy, provide higher data sharing ability, and require high independence of program and data, when the logical structure of data is changed, the physical structure of data is not involved. Nor does it affect the application to reduce the cost of application development and maintenance. Database technology is developed on the basis of such an application requirement.
The above content can be seen that the database system is based on the development of the file system.
Two, the difference between file system storage and database system storage and connection
The essential difference between a file system and a database system is:
The file system organizes the data into separate data files, realizes the structure in the record, but the whole unstructured, and the database system realizes the structure of the whole data.
In the file system, data redundancy is large, waste storage space, easy to cause inconsistent data, but in the database system, the data is oriented to the entire system, data can be used by multiple users, multiple applications shared, reducing data redundancy. Files in a file system are services for a particular application, and when you want to modify the logical structure of the data, you must modify the application, modify the definition of the file structure, the lack of independence between the data and the program, the database system, the The DBMS's level two image realizes the physical and logical independence of data, separates the definition of data from the program, and reduces the maintenance and modification of the application.
Both the file system and the database system can save data for a long time, and the data management software manages the data, and the database system is developed on the basis of file system.
The database system primarily manages the storage, transaction, and operation of the database. The file system is the subsystem of the operating system to manage files and storage space, mainly the allocation of the files of the cluster, disk block or build FAT, management space space. In general, the database system calls the file system to manage its own data files, but some database systems can manage their own data files, even on bare devices. The file system is required by the operating system, and the database system is only necessary for database management and application.
Iii. Summary
In summary, there are differences and linkages between file systems and database systems.
The difference is:
(1) The file system uses the file to keep the data on the external memory, and the database system uses the database to store the data uniformly.
(2) There is a certain connection between the program and data in the file system, and the separation of the program and data in the database system.
(3) The file system uses the access method of the operating system to manage the data, and the database system uses DBMS to manage and control the data uniformly.
(4) The file system realizes the data sharing in the file unit, and the database system realizes the data sharing in the record and the field.
The link is:
(1) is the management technology of data organization.
(2) The data management software is used to manage the data, and the program and data are converted by means of access.
(3) The database system is developed on the basis of the file system.
In short, the file system storage and database system storage each have pros and cons, two storage methods are widely used in the real world of various fields.
File system Storage data, and database system storage data differences