The Components of the DBMS Environment 1. Hardware – can range from a PC to a network of computers. 2. Software – DBMS, operating system, network software (if necessary) and also the application programs. 3. Data – data constitutes the database's central component through which information is generated 4. Procedures – instructions and rules that should be applied to the design and use of the database and DBMS. – designed to accomplish desired activities 5. People – perform different functions within the environment
Divided by function, database management systems can be broadly divided into six parts: (1) mode translation: Data definition language (ddl). Use it to write the database model is translated into internal representation. The logical structure of the database, integrity constraints, and the physical storage structure of the data stored in the internal dictionary. Database, a variety of data manipulation (such as search, modify, insert and delete, etc.) and database maintenance and management are based on database schema based. (2) application of the compilers: To access the database contains the statement that applications compiled to run in the dbms support of the object program. (3) Interactive query: Provides easy to use interactive query language, such as sql. Dbms responsible for implementing the query command and query results displayed on the screen. (4) data organization and access: Provide data in the external storage device, the physical organization and access methods. ⑸ services operation and management: Provision of services operation and management and operational logs, transaction monitoring the safety of operation and data integrity checks, transaction concurrency control and system recovery functions. (6) Database maintenance: Database administrators to provide software support, including data security control, integrity protection, database backup, database restructuring and performance monitoring maintenance tool. Based on the relational model database management system has been perfected and has been widely used in all walks of life as a commercial software. It is in all families, distributed server architecture in the application of multi-user environment, so that further expansion of the application of database systems. With the new data model and data management techniques to promote the implementation can be expected dbms software will also update and improve the performance, applications will also be further broadened.
DATA data is integrated and shared by many users. A database is a representation of a collection of related data. Underlying principles: Hierarchical, network, relational or semantic. • SOFTWARE the components of a database management system: Data definition and data manipulation. • USERS application programmers, non-computer science expert and experienced user. • HARDWARE consequences for the architecture of a database system. Developments: Time sharing, file server, client/server.
tables to store data reports and forms to get data into and out of tables querys t extract data dedicated interface gives various levels of access it mananges data, organises it, and extracts it. It copes with data integrity, consistency, and there should be zero redundancy and also there is an emphases on data independence
DATA data is integrated and shared by many users. a database is a representation of a collection of related data. underlying principles: Hierarchical, network, relational or semantic. • SOFTWARE the components of a database management system: Data definition and data manipulation. • USERS application programmers, non-computer science expert and experienced user. • HARDWARE consequences for the architecture of a database system. developments: Time sharing, file server, client/server.