A component is a self-contained piece of software in a database system. A component can be defined at different levels of coarseness. At the coarsest level, the components of a relational database management system consist of the client communications manager, the process manager, a relational query processor, a transactional storage manager, and utilities .
The components of a relational database management system can be further refined into subcomponents . The client communications manager consists of local client protocols and remote client protocols. The process manager consists of admission control and dispatch and scheduling. The relational query processor consists of query parsing and authorization, query rewrite, query optimization, plan execution, and DDL and utility processing. The transactional storage manager consists of access methods, a buffer manager, a lock manager, and a log manager. Sub-components that comprise the...