In this Lesson you will learn-
- 1. Concept of data and information.
- 2. Basic elements of database.
- 3. Advantages and disadvantages of database.
- 4. Application areas of database.
Data: Data is raw, unorganized facts that need to be processed. For getting desired output in a processing data is used as input. Data can be defined as a representation of facts and it is the smallest part of information. Data is represented with the help of characters such as alphabets (A-Z, a-z), digits (0-9) or special characters (+,-,/,*,<,>,= )
Classification of data:
Information: When data is processed, organized, structured or presented in a given context so as to make it useful, it is called information. Information is the processed data on which decisions and actions are based.
Examples of data and information: The marks of every subject of a student is called data. On the other hand, the report or result of a student by calculating the marks of all subjects is called information.
Database: A database is an organized collection of related data, stored and accessed electronically. A database is used by an organization as a method of storing, managing and retrieving information. Modern databases are managed using a database management system (DBMS).It may have single or related multiple table in a database.
The elements of database:
- Attribute/Field/Column: A field is a part of a record that contains a single piece of data for an object in the record. On the other hand, the columns of a table are called attributes, which are the describing characteristics of each record.
- Attribute value: The value of a particular attribute is called attribute value.
- Entity/Record/Tuple/Row: A record is a group of fields within a table that are relevant to one particular person, company, or item in a database. Records appear as rows in the database table.
- Table/Entity set: A database table is composed of records and fields that hold data. Tables are also called datasheets. Each table in a database holds data about a different, but related, subject.
Data Hierarchy: Data hierarchy is a systematic organization of data mainly in a hierarchical form. Data organization basically involves bit, byte, field, record, file, and database.
Advantages and disadvantages of database:
- 1. Reduced data redundancy
- 2. Reduced updating errors and increased consistency
- 3. Greater data integrity and independence from applications programs
- 4. Improved data access to users through use of host and query languages
- 5. Improved data security
- 6. Reduced data entry, storage, and retrieval costs
- 7. Facilitated development of new applications program
- 1. Database systems are complex, difficult, and time-consuming to design
- 2. Substantial hardware and software start-up costs
- 3. Damage to database affects virtually all applications programs
- 4. Extensive conversion costs in moving form a file-based system to a database system
- 5. Initial training required for all programmers and users
Application areas of database:
- 1. Banking
- 2. Airlines
- 3. Library
- 4. Telecommunication
- 5. Educational Institution
- 6. Production and distribution
- 7. Human Resource (HR)
- 8. Automated Teller Machine (ATM)
- 9. Stock/Share Market
- a. What is data?
- a. What is information?
- a. What is database?
- a. What is attribute/field?
- a. What is field/entity/record?
- b. Field and record are not same-explain it.
- b. Field is not dependent on record- explain it.