The document outlines the overall system structure of a Relational Database Management System (RDBMS), divided into three main components: query processor, storage manager, and data structure. It details various functionalities, including the roles of the DML compiler, DDL interpreter, authorization and integrity manager, and transaction manager within the system. Additionally, it discusses the significance of data files, data dictionaries, indices, and statistical data in enhancing query processing and management.

1. Overall system structure in RDBMS
BY SUBHASHENI A

2. Introduction
 Database Management System are very large and divided into modules.
 Services are also provided by operating system of host computer
 Overall system structure may be divided into 3 types
1. Query processor
2. Storage manager
3. Data structure

3. Query processor
 DML compiler – translates Data Manipulation Language into query engine
instructions.
 Embedded DML pre Compiler – converts the DML statements in an
application program to normal procedure calls in the host language.
 DDL interpreter – interpreter Data Definition Language statements and
records then in a set of tables.
 Query Evaluation Engine

4. Storage Manager
 Authorization and integrity manager – Tests for the satisfaction of integrity
constraints and checks the authority of user to perform various actions
 Transaction Manager – It ensures the database remains in a consistent
state despite system failures.
 File Manager – Responsible fornthe allocation of space on the disk storage
system.
 Buffer Manager – Manages the data coming into and out of the system
including the cache data.

5. Data Structure/Disk Storage
 Data files- it is database itself
 Data Dictionary – The metadata about the structure of the database.
Actually it is a critical element in the Database Management System.
 Indices – It is used to provide fast access to the data.
 Statistical Data – The query processor use this to optimize queries