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Lesson 7The relational database management system
ObjectiveWhat are the functions of an RDBMS?

Relational Database Management System

A database management system (DBMS) is a software interface that sits between a database and a user, or between a database and an application (such as an inventory system). Different DBMSs support different database models and different
  1. DDLs [Data Definition Language] and
  2. DMLs [Data Manipulation Language].
A typical DBMS creates, manipulates, modifies, and maintains a database.

Relational Database Management System (RDBMS)

A relational database management system (RDBMS) supports the relational model. It performs the same basic functions as those listed for a DBMS. SQL is the data definition and data manipulation language that is packaged with an RDBMS. The following Slide Show walks you through the major functions of a RDBMS. Use the forward and back arrows to navigate through the series of images.

The SQL component in an RDBMS creates the relational database and its structures.
1) The SQL component in a RDBMS creates the relational database and its structures

The SQL in a RDBMS allows access to data in a variety of ways
2) The SQL component in a relational database management system allows access to data in a variety of ways.

The SQL in a RDBMS provides the means to make changes to database records
3) The SQL component in a RDBMS provides the means to make changes to database records.

Has built-in security, as well as utilities to perform routine databse backups
4) A RDBMS has built-in security, as well as utilities to perform routine databse backups.

A feature rich RDBMS provides tools to generate invoices, payroll checks, financial reports, and other userful documents.
5) A feature rich RDBMS provides tools to generate invoices, payroll checks, financial reports, and other userful documents

  1. SQL component in a RDBMS
  2. Allows access to data in a variety of ways
  3. Provides the means to make changes to database records
  4. Built-in security and utilities to perform routine DB backups
  5. RDBMS provides tools to generate invoices, payroll checks, and financial reports
RDBMS Functions

RDBMS Management

One RDBMS can manage many relational databases.
Oracle, Microsoft, IBM, MySQL, and Sybase have comprehensive RDBMSs available on the market.
Each company packages its product(s) with utilities to enhance RDBMS capabilities and performance. Product prices vary widely among these top competitors.
The next lesson discusses the concept of database change management.

Main functions of DBMS

A database management system (DBMS) is a collection of programs that manages the database structure and controls access to the data stored in the database. In a sense, a database resembles a very well-organized electronic filing cabinet in which powerful software, known as a database management system, helps manage the cabinet’scontents.
  1. Data storage: A DBMS provides a systematic and organized way of storing data. It defines the structure of the database in the form of tables, schemas, or other data structures, depending on the type of DBMS (relational, hierarchical, network, etc.).
  2. Data retrieval and querying: A DBMS enables users and applications to retrieve and access data efficiently using a query language, such as SQL for relational databases. It processes queries, optimizes their execution, and returns the requested data to the users or applications.
  3. Data manipulation: A DBMS allows users and applications to insert, update, and delete data. It ensures that data manipulation operations are performed in a consistent and atomic manner, preserving data integrity.
  4. Data consistency and integrity: A DBMS enforces data consistency and integrity rules, such as primary key, foreign key, and unique constraints. It ensures that the data in the database adheres to these rules and maintains referential integrity across related tables or entities.
  5. Transaction management: A DBMS manages transactions, which are a sequence of operations that must be executed atomically (all or nothing) and in isolation from other transactions. It ensures that the database remains in a consistent state even in the case of concurrent transactions, system failures, or errors, adhering to the ACID (Atomicity, Consistency, Isolation, Durability) properties.
  6. Concurrency control: A DBMS implements concurrency control mechanisms to manage simultaneous access to the database by multiple users or applications, preventing conflicts and ensuring data consistency.
  7. Security and access control: A DBMS provides security features to protect data from unauthorized access, modification, or deletion. It implements access control mechanisms, such as user authentication, authorization, and role-based access control, to restrict access to data based on user privileges.
  8. Backup and recovery: A DBMS includes backup and recovery features to ensure data durability and resilience. It allows for regular backups of the database and provides mechanisms to recover data in case of hardware or software failures, data corruption, or human errors.
  9. Performance optimization: A DBMS optimizes the performance of data storage, retrieval, and manipulation operations through techniques such as indexing, query optimization, and caching.
  10. Data import and export: A DBMS provides tools and utilities to import data from external sources or export data to various formats, facilitating data migration, integration, and analysis.

The primary functions of a DBMS are to manage and control data storage, retrieval, manipulation, consistency, integrity, transaction management, concurrency control, security, backup and recovery, performance optimization, and data import/export. These functions ensure that the database is efficient, reliable, and secure, meeting the needs of users and applications.

RDBMS - Exercise

Before moving on to the next lesson, click the Exercise link below to check your knowledge of the functions of an RDBMS.
RDBMS - Exercise

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