Learning Outcome 4

Database Management system

What is database?
A database is a collection of information organized to provide efficient retrieval.The collected information could be in any number of formats (electronic, printed, graphic, audio, statistical, combinations).

What are the function of database?
The function is to store, organize and control the data.

Database component
There are two types of component. They are
(1) Data item : It is field in data processing and it is a piece of information.
(2) Schema : It describes the organization of data and relationships within the database.
                   The schema consists of definitions of the various types of record in the
                   database, the data-items they contain and the sets into which they are
                   grouped. It known as ERD.

Database Architecture
The architecture of a modern database consists of :
1. Actual database
2. Hardware to process and store the data
3. Software to manipulate the contents
4. People to administer the access, control and modification of data.

Database Management System (DBMS)
What is database management system?
A DBMS is a database program. It is a software system that uses a standard method of cataloging, retrieving, and running queries on data. The DBMS manages incoming data, organizes it, and provides ways for the data to be modified or extracted by users or other programs.
Eg. Microsoft access, SQL server, FileMaker, FoxPro, etc...

Type of Database Language
(1) DDL ( Data Definition Language)
(2) DML ( Data Manipulation Language)

DML

DDL

Components of DBMS
There are six components such as
1. Field 
    It is a specific piece or category of data such as first name, last name, city, state, subject or birth date.
2. Record
    It is a group of related fields that describes a person, place, thing or transaction such as customer, student, location, product or sale.
3. Table 
    It is a collection of records for a single subject such as student, products or sales
4. Key field
   It is a field that contains unique information for each record, such as student ID.
5. Relational database 
    It is a multiple tables that are linked together to address a business process such as managing timetable, course, and students.
6. Objects
    The part of an Access database that help you view, edit, manage, and analyze the data: tables, queries, forms, reports, macros, and modules.
                  What are the users of database management system (DBMS) ?
The users of DBMS are end user, application programmers, database administrator.

What is database model?
A database model is a type of database model that determines the logical structure of a database and fundamentally determines in which manner data can be stored, organized, and manipulated.

Types of database model
1. Hierarchical database
2. Network database
3. Relational database
4. Object- relational database

Hierarchical database
A hierarchical database model is a data model in which the data is organized into a tree-like structure. It also known as one to many relationship.

 

Network database

The network model is a database model conceived as a flexible way of representing objects and their relationships. Its distinguishing feature is that the schema, viewed as a graph in which object types are nodes and relationship types are arcs, is not restricted to being a hierarchy or lattice.

Relational database
In relational database, data is organized in the form of rows and columns in a table. The table are referred to as relations in relational data model. The relational data model is implemented through a sophisticated relational database management system (RDVMS). It is useful for small database system.