Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/lsp4you/public_html/connect.php on line 2 LSP4YOU - Learner's Support Publications
DBMS BCA Unit-1 DBMS - Introduction The File Based System Database System vs. File Based System Limitations of File Based System Database System Components Advantages of Database Approach DBMS ARCHITECTURE Three Level Architecture of DBMS External or View Level Conceptual Level Internal or Physical Level Data Independence Physical DBMS Architecture Database Manager Database Users Database Administrator (DBA) Roles and Responsibilities of DBA Data Models The Relational Data Model The Network Data Model The Hierarchical Data Model MySQL Installation in Ubuntu


Physical DBMS Architecture

  • Describes the software components used to enter and process data.
  • How these s/w components are related and interconnected.


Database Management System

  • 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.