Data Data is a collection of facts, such as numbers, words, measurements, observations or even just descriptions of things. Data can be qualitative or quantitative. Information Information is data that has been processed in such a way as to be meaningful to the person who receives it. it is any thing that is communicated.

1. Database Fundamentals
Submitted By
Laila Arzuman Ara
SEID:266759
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2. Topics
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 Introduction to Database
 Database Management System(DBMS)
 Database Schema
 Data Model
 Relational Database Management System(RDBMS)
 Keys
 SQL

3. Introduction to Database
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 Data
 Data is a collection of facts, such as numbers, words, measurements, observations or
even just descriptions of things.
 Data can be qualitative or quantitative.
 Information
 Information is data that has been processed in such a way as to be meaningful to the
person who receives it.
 it is any thing that is communicated.

4. Introduction to Database cont…
 Database
 A database, in the most general sense, is an organized collection of data. More
specifically, a database is an electronic system that allows data to be easily accessed,
manipulated and updated.
 Alternatively referred to as a databank or a datastore, and sometimes abbreviated as a
DB.
 A database is built and maintained by using a database programming language. The
most common database language is SQL.
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5. Database Management System(DBMS)
 Database Management System(DBMS)
 A database management system (DBMS) is a software package designed to define,
manipulate, retrieve and manage data in a database.
 A DBMS generally manipulates the data itself, the data format, field names, record
structure and file structure.
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6. Database Management System(DBMS) cont..
A database is made up of several main components.
 Tables
 The table is the basic data-storage unit in a relational database.
 Tables consist of columns and rows.
 Row
 A row, also called a record, represents a set of data about a specific item.
 Every record in a table has exactly the same structure, but of course different data.
 Column
 A column is a specific set of values in a table of the same type.
 It defines a specific attribute of the table or data.
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7. Database Management System(DBMS) cont..
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Table
a field
a record

8. Database Management System(DBMS) cont..
 Advantages
 Reduced data redundancy
 Reduced updating errors and increased consistency
 Greater data integrity and independence from applications programs
 Improved data access to users through use of host and query languages
 Improved data security
 Reduced data entry, storage, and retrieval costs
 Facilitated development of new applications program
 Disadvantages
 Database systems are complex, difficult, and time-consuming to design
 Substantial hardware and software start-up costs
 Damage to database affects virtually all applications programs
 Extensive conversion costs in moving form a file-based system to a database system
 Initial training required for all programmers and users
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9. Database Schema
 A database schema typically shows the different tables, their fields and the relationship
between them and other tables.
 In addition to tables and fields, a database schema defines a database's:
 Indexes
 Views
 Triggers
 Database links
 Events
 Procedures
 Functions
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10. Database Schema cont.…
 Schema is of three types:
 Physical schema
The design of a database at physical level is called physical schema, how the
data stored in blocks of storage is described at this level.
 logical schema
Design of database at logical level is called logical schema, programmers and
database administrators work at this level
 view schema.
Design of database at view level is called view schema. This generally describes end
user interaction with database systems.
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11. Data models
 Data Model is a logical structure of Database.
 It describes the design of database to reflect entities, attributes, relationship
among data, constrains etc.
 There are several types of data models in DBMS.
 Object based logical Models
 Record based logical Models
 Physical Data Models
 Entity–relationship model (ER model)
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12. Data models cont.…
 Entity–relationship model (ER model)
 An ER diagram shows the relationship among entity sets. An entity set is a group of
similar entities and these entities can have attributes.
 Lets have a look at a simple ER diagram to understand this concept.
 This model is based on three basic concepts:
 Entities
 Attributes
 Relationships
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13. Relational Database Management System(RDBMS)
 RDBMS stands for relational database management system.
 It is based on the relational model.
 A relational model can be represented as a table of rows and columns. A relational
database has following major components:
1. Table
2. Record or Tuple
3. Field or Column name or Attribute
4. Domain
5. Instance
6. Schema
7. Keys
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14. Keys
 Key plays an important role in relational database.
 It is used for identifying unique rows from table. It also establishes relationship
among tables.
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