Describes the software components used to enter and process data.
How these s/w components are related and interconnected.
Data Definition Language(DDL) - Set of commands required to define the format of data.
Data Manipulation Language(DML) - Set of commands that modify, process data.
DML Precompiler - It converts DML statements embedded in an application program to normal procedural calls in the host language. It interacts with the query processor in order to generate the appropriate code.
DDL Compiler - It converts DDL statements into a set of tables containing metadata tables – which are in a form that can be used by other components of the DBMS. These are stored in system catalog or data dictionary.
File Manager - Manages the allocation of space on disk storage.
Query Processor - Responsible for receiving query language statements and changing to a form the DBMS can understand. It has two parts : parser and query optimizer.