Database System Structure
The functional components of the database system can be divided into two components: the Storage manager and the Query processor. 1. Storage Manager A storage manager is a program which provides interface between low – level data, the application programs and queries submitted to the system. It also interacts with the file manager. The storage manager translates various DML statements into low – level file – system commands. It is also responsible for storing, retrieving, and updating the data stored in the database. The components of storage manager include: Authorization and integrity manager : checks the authority of the users to access the data and tests for the satisfaction of integrity constraints. Transaction manager : ensures consistency of database despite system failures, and concurrent transaction execution without conflict. File manager : manages space allocation on disk storage and data structures used to represent the information stored on disk. Buffer manager :