Database Concepts | Metadata in DBMS | Data Item | Database | DBMS

Data:

In simple words, data is raw facts or figures or entity. For example, data relating to an individual would be the person’s name, birth date, address, telephone number etc.

Data, in the context of databases, refers to all the single items that are stored in a database, either individually or as a set. Data in a database is primarily stored in database tables.

For example, in a banking application, data is the of account numbers, customers’ names, addresses, bank transactions and so on.

Metadata:

Metadata is data about data. It means it is a description of the data. It helps to understand the data. Metadata is an explanation or summary of what the data is.

A simple example of metadata is,  a book might include collection of information like a title, author name, publisher and copyright details, table of contents, index, page numbers etc.

 

Data Item:

Each piece of information about an entity, such as name of a person or address, age or name of a product or the price is a Data Item.

A data item is a single unit of data. This term may refer specifically to the smallest possible unit of information, or more generally to a single entry or field.

When it is the smallest possible unit of meaningful information, it represents a very small component of a larger set of data. In an address, each part of the address is its own data item and can be looked at separately.

Files:

A File is a collection of related records used as a single unit is called file. File is also known as data set.  Files are stored on different storage media like hard disk, optical disk etc.

Example, “Student” file may contain the records of hundreds employees.

Database:

A database is a collection of related data. It represents some aspects of the real world. A database is a systematic collection of data related to a particular subject or purpose, such as tracking customer orders or maintaining a music collection.

A database is an organized form of data for easy access, storing, retrieval and managing of data. It can be of any size and complexity. A simple example of a database is university database; it contains information about students, courses etc.

Features of Database:

Database is a solution to overcome the drawbacks of conventional file processing systems. There are many features of a database.

The main features are listed below:

1. The database helps in organizing data in an organized way.

2. The use of database eliminates data redundancy (data duplication) and provides data consistency.

3. Databases facilitate sharing of data.

4. Databases enforce standards.

5. Integrity can be maintained through databases.

6. Data security gets improved with the use of a database system.

7. Data can be easily managed by using a database system.

8. The database system provides multiuser data access.

 

Database Management System(DBMS):

A database management system (DBMS) is collection of program that enables user to create and maintain a database. The DBMS is hence a general purpose software system that facilitates the process of defining, constructing and manipulating database for various applications.

DBMS also provides protection and security to the databases. It also maintains data consistency in case of multiple users.

A database management system (DBMS) is software that allows creation, definition and manipulation of database. DBMS allows us to store, process and analyze data easily. Ex. Oracle, MySql, SQL Server etc.

Features (Characteristics) of Database Management System:

A database management system has following characteristics:

1. Data stored into Tables: In database management system, data is stored into tables, created inside the database. DBMS also allows having relationships among the related tables which makes the data more meaningful and connected.

2. Reduce Redundancy: This is one of the important features of the DBMS that it reduces the redundancy. Redundancy means unnecessary repetition or duplicacy of data in database. To reduce the redundancy DBMS uses  Normalization which divides the data in such a way that repetition is minimum.

3.  Data Consistency: The term data consistency means state of data should be consistent means it should be correct at any instant of time. A DBMS provide greater consistency as compared to earlier forms of data storing applications like file processing system.

4. Support Multiple user and Concurrent Access: DBMS support the concurrent access of the database to the multiple users.  Multiple users can work on the database at the same time and still maintained the consistency. Here the term consistency represents the correctness of the database.

5. Query Language: DBMS support to SQL  using which data can be easily retrieved, inserted, deleted and updated in a database.

6. Security: DBMS give s the facility to take care of the security of data, protecting the data from un-authorized access. In a typical DBMS, we can create user accounts with different access permissions, using which we can easily secure our data by restricting user access.

Advantages of DBMS

• Reduces data redundancy (duplication of data).
• Database facilitate sharing of data
• Restricting unauthorized access
• Enforcing integrity constraints
• Providing backup and recovery
• Controls data inconsistency to a large extent.
• Enforce standards
• Centralized databases can ensure data security

Application of DBMS: 

There are so many fields where we use  database management system. Some of the applications where database management system uses are: 

Railway Reservation System: The railway reservation system database plays a very important role by keeping record of ticket booking, train’s departure time and arrival status. Also if trains get late, then people get to know it through the database updates.

Airline Reservation System: Just like the railway reservation system, airlines also need DBMS to keep records of reservation and schedule information, flights arrival, departure and delay status.

Library Management System: There are lots of books in the library so it is very difficult to keep record of all the books in a copy or register. Now-a-days it’s become easy to track each book and maintain it because of the database. DBMS is used to maintain all the information related to book issuing date, name of the book, author and availability of the book.

Banking: Banking is one of the main applications of databases. There will be a thousand transactions through banks daily. This is all possible just because of DBMS that manages all the bank transactions. Customer information, account activities, payments, deposits, loans all of these are done with the help of DBMS.

Education Sector: Now-a-days examinations are done online. The universities and colleges maintain all these records through DBMS. Student’s information, course registrations details, results, courses and grades etc all these information are stored in the database.

Social Media Sites: We all use social media sites to share our views and connect with our friends. By filling the required details we are able to access social media platforms. Many users sign up daily for these social media sites such as Facebook, Twitter, Pinterest, Instagram, WhatsApp etc. All the information related to the users are stored and maintained with the help of DBMS.

Online Shopping: Online shopping has become a big trend these days. Everyone wants to shop from home through web based shopping sites, for example, Amazon, Flipkart, Snapdeal.  All these products are added and sold only with the help of DBMS. Purchase information, invoice bills and payment all of these are done with the help of DBMS.

Human Resource Management: Big firms or organizations have many employees working under them. The management keeps records of each employee’s salary, tax and work through DBMS.

Manufacturing: Manufacturing companies make various kinds of items and sell them on a daily basis. To keep records of all the details about the products like quantity, bills, purchase,  inventory status etc., DBMS is used.