What is Data?
Data is a real-world entity or an object.
Data is a distinct piece of information or facts that need to be processed. It can
be in any form like text, number, picture, measurements, and bytes.
Example: Ankit, Delhi, 12, 80.
What is Information?
When data are processed, organized, structured, and interpreted in
a given context, so as to make them useful and meaningful, they are called
Example: Name – Ankit, City – Delhi, Class – 12, Marks – 80.
What is Database?
A database is an organized collection of inter-related data, which helps in insertion, deletion, and retrieval of data efficiently. The database is also used to organize the data or information in the form of tables, views, schemas, reports, etc.
Note: Using the database, you can easily access, update, and delete any information.
Database Management System (DBMS)
A database management system or DBMS is a software used for creating and managing the data in the database easily and effectively. It is basically a set of programs that allow users to store, modify/update, and retrieve information from the database as per the requirements. DBMS also provides security and protection to the database. DBMS acts as a middle layer between the database and the user.
Example: MySQL, MS SQL Server, Oracle, SQL, DB2, Microsoft Access, etc. are different types of database management system.
Characteristics of DBMS
There are various characteristics of a database management system, but following are some important characteristics:
- A database management system (DBMS) should be able to store any kind of data in a database.
- Any database management system should be able to support ACID (atomicity, consistency, isolation, durability) properties.
- The Database management system allows more than one users to access the same database at the same time.
- Backup and recovery are the two main methods that allow users to protect their data from damage or loss.
- It provides multiple views for different users in one organization.
- DBMS follows the concept of normalization to minimize the redundancy of a relation.
- It provides users query language, using which they can easily insert, retrieve, update, and delete the data in a database.
Advantage of DBMS
- Minimal data redundancy or data duplicacy.
- Easy access to data from the database using the query language.
- DBMS provides backup and recovery methods which create an automatic backup of data from software and hardware failures and restores the data if required.
- Minimized data consistency.
- Better data integration.
- DBMS can applies integrity constraint to the data in the database.
- DBMS increases consistency and reduces updating errors.
Disadvantages of DBMS
- A database management system is complex and time consuming to design.
- Cost of software and hardware is high to run DBMS software.
- DBMS consumes a large amount of main memory as well as a huge amount of disk space to make it run efficiently.
- If the database is damaged because of any software or hardware failure, all the application programs will be implicitly affected, which are dependent on it.
- Initial training is required for all the users and programmers to use the DBMS software.
Database Management System (DBMS) Topics
1 DBMS Concepts
- What is Database Management System?
- Components of DBMS.
- Applications of DBMS
- The difference between file system and DBMS.
- Types of DBMS.
- Architecture of DBMS.
- Schema, Sub schema and Instance in DBMS.
- Three Schema Architecture.
- DBMS Languages.
2 DBMS ER Model
3 DBMS Relational Model
- Codd’s rule of DBMS
- Relational DBMS concepts
- Relational Integrity Constraints
- DBMS keys
- Convert ER model into Relational model
- Difference between DBMS and RDBMS
- Relational Algebra
- DBMS Joins
4 DBMS Normalization
6 DBMS Transaction
- What is Transaction?
- States of transaction
- Properties of transaction
- Concurrent execution and its problems
- DBMS schedule
- DBMS Serializability
- Deadlock in DBMS
- Concurrency control protocols
7 DBMS Indexing
- What is Indexing?