Database System Environment

Introduction

In this video, we will be discussing the database system environment and the types of software components in a database management system.

Types of Software Components in DBMS

• The Database Administrator (DPA) and its staff use Data Definition Language (DDL) to specify schemas.

• The DDL compiler processes the schema definition specified in the data definition language and stores these definitions or descriptions of the schema in the catalog.

• The Query Compiler handles high-level queries by creating a database access code and then calls a runtime database processor for executing that code.

• The Pre-compiler extracts all the DML commands from an application program written in a host programming language like C, C++, Java, etc., and sends them to the DML compiler where they are compiled into an object code for access to the database.

• The Runtime Database Processor handles any kind of database accesses at runtime by receiving retrieval or update requests and carrying them on to store data on disk.

• The Store Data Manager controls access to information stored on disk and carries out data transfer between disk and main memory.

Database System Utilities

Most database management systems have utilities that help manage databases.

Common Utility Functions

• Loading utility is used to load existing data files into the database by reformatting it based on source format of data file mentioned to utility.

• Backup utility creates backup copy of database which can be restored in case of any system failures.

• File Reorganization Utility is used to reorganize a database file into different file organization for improved performance.

• Performance Monitoring Utility monitors usage statistics of the database and provides complete statistics of the performance of the database to the database administrator.

Other Utilities

• There are other utilities for sorting files, monitoring user access, and performing other functions.

Database System Environment

In this section, we will discuss the different component modules of DBMS.

Data Dictionary

• The data dictionary is used to store catalog information.

• It also stores other information like descriptions of the application program user information, etc.

• This system is also called an information repository because it has information that can be accessed directly by the users or the database administrators when required.

Application Development Environments

• These systems provide an environment for developing a database application.

• Examples include J Builder system and Power Builder system.

Communication Software

• DBMS needs communication software where it allows users remote access to the database through computer terminals or workstations or their local personal computers.

• They are connected to the database site through phone lines or local area networks (LAN).

Conclusion

This was all about the database system environment which included the different component modules of DBMS.