“Database is a collection of Data.
And Management System is a set of programs to store and retrieve those data.”
Database systems are basically
developed for large amount of data. When dealing with huge amount of data,
there are two things for require optimization: Storage of data and Retrieval of
data.
Data is a collection of raw facts, whereas raw facts is means “the collection of numbers, words, special Symbols and
figures.
“Data never provide the meaningful
statements.”
What is Table and Record?
Collection of related records, is called Table.
Collection of related data items is
called Record.
Example: Below given table contains three data
items had no meaning. But if we organize them in the following way, then they
collectively represent meaningful information.
What is Information?
Processing the Data is called as
information.
“Information always provide the
meaningful statements to the user.”
What is a Management System?
A management system is a set of rules
and procedures, with the help of you can create, organize and manipulate the
database. It also helps us to insert, select, modify and delete data items in
the database. The management system can be either manual or computerized.
The management system is important
because without the existence of some kind of rules and regulations. It is not
possible to maintain the database. We have to select the particular attributes
which should be included in a particular table, the common attributes to create
a relationship between two tables, if a new record has to be inserted or
deleted then which tables should have to be handled etc.. These issues must be
resolved by having some kind of rules to follow, in order to maintain the
integrity of the database.
“A user is a person who uses a
computer or network service. Users generally use a system or a software product
without the technical expertise required to fully understand it.”
The users of a DBMS can be broadly
categorized as follows −
1.
Database Administrator (DBA): DBA takes care of the administrative tasks of DBMS as the name
suggests and his major responsibilities are given below.
(1) Management of information
(2) Liaison with users
(3) Enforcing security and integrity
rules
(4) Database backup and recovery
(5) Monitoring database performance
2.
Database Designers: Database
designers design the database components
3.Application Programmers: Application
programmers write programs to access/insert/ update /delete data from the
database by making use of the various database components.
4. End
Users: End users use
DBMS.
A
Database is a computer based record keeping system which is used to record,
maintain and retrieve data. It is an organized collection of interrelated
(persistent) data.
What type of data is stored in the database?
In a
database, we would be grouping only related data together and storing them
under one group name called a table. This helps in identifying which data is
stored where and under what name. It reduces the time to search for a
particular data in a whole database. For example, Student, Teacher, Class,
Subject, Employee, Department etc. form individual tables.
Types of Databases:
There are two types of
database:
1. Centralized Database
2. Distributed Database
1. Centralized Database:
In
Centralized database system, all data is stored at a single site. It offers a
great control in accessing and updating data. However, failure chances are high
because the system depends on the availability of resources at the central
site.
Example:
- Some major banks do all their
processing on a mainframe, in some cases in a different country.
- Clients may use several Airline reservation
systems need to be centralized to avoid double bookings.
- Airline reservation systems need
to be centralized to avoid double bookings.
Advantages:
- Increased reliability and availability
- Modular (incremental) growth
- Lower communication costs
- Faster Response
Disadvantages:
- Software cost and complexity
- Processing overheads
- Data integrity
2. Distributed Database: In Distributed Database system, the database is stored on several computers. Computers in a distributed system may communicate with one another through internet/intranet/telephone lines etc. Most of the distributed
systems will be geographically separated and managed. Distributed databases can
also separately be administered.
Example: Telephone
Network and Cellular Networks.
Advantages:
- Minimize
communications
- Costs
- Local
control
Disadvantages:
- Adds
to complexity and cost
- Processing
overheads
- Data
Integrity
DBMS
What is Database Management System?
“DBMS is a tool or software which can
be used for managing and maintaining data in the database.”
We can
define DBMS like this:
A DBMS is a collection of
interrelated data and set of programs to store & access this data in an
easy and effective manner.
Advantages of a DBMS:
- Data
independence
- Reduced
data redundancy
- Increased
security
- Better
flexibility
- Effective
data sharing
- Enforces
integrity constraints
- Enables
backup and recovery.
Disadvantages of a
DBMS:
- Cost of
Hardware and Software
- Cost of Data
Conversion
- Cost of
Staff Training
- Appointing
Staff
- Database
Damage
Services provide by a DBMS :
- Data
management
- Data
definition
- Transaction
support
- Concurrency
control
- Recovery
- Security
and integrity
- Facilities
to import and export data
- User management
- Backup
- Performance
analysis
- Logging
- Audit
- Physical
storage control
Difference between File
based Data Storage System and DBMS:
Models of Database Management
System:
DBMS contain the
following Six Models:
1. File
Management System (FMS)
2. Hierarchical Management
System (HMS)
3. Network Database
Management System (NDBMS)
4. Relational
Database Management System (RDBMS)
5. Object
Relational Database Management System (ORDBMS)
6. Object
Oriented Relational Database Management System (OORDBMS)
1. File Management System (FMS): FMS is a first
model of the database which was introduced in 1950’s, in this model data will
be stored a sequential manned continuing stream of characters' manners. Ex.
Drawback :
- This is no security to file information.
- He does not support data type & index
mechanism.
- To maintain data in consistency(is no proper order)
2. Hierarchical Management System (HMS): Hierarchical Management
System is a second model of the database which was introduced IBM, where
developing a project a project is called as
information management system in 1950.
In this model, the data will be store in the
form of free structure and it contain the following levels:
. The Root: It
will represent database location in DB name.
The Parent: It
will represent table/entity name.
The Child: It
will represent columns/attribute name.
Drawback :
- In this model only one person interact with the database server simultaneously
at a time.
- If we add a new value to at existing structure then the user has
to recon structure the entire structure.
- This process will leads time consuming and burden of the
programmer will be increased
- Its support Data Type & index mechanism.
- To maintain consistency of the data (Arranging the values systematized)
- Retrieving data is faster than FMS Model.
3. Network Database Management
System (NDBMS): Network Management
System is a third model of the database which was introduced IBM in 1969.
In this model
the data will be stored in the form of free structure and integrated with network
of environmental.
Drawback :
- There is no proper security of the centralized DB (CDB) Server.
- The Database will be increased (increasing duplicate value).
- Mode memory will occupy.
- The application system is performed will be reduced.
Advantage:
- In NDBMS model multiple user can interact with the DB at a time and also multiple users can store the data at a time.
- If we add a new value into an existing structure by using Pointer.
NOTE: "The above,
all models are outdated industries in real time."
4. Relational Database Management System (RDBMS): RDBMS
is a relational model which words introduce parts, which was German Scientist
Mr. E.F. Codd in 1970’s.
Here
Relation can be defined as the normal test between objects, If
any database which will be stored, the form of a popular format. The
database is a formal RDBMS protector.
The
relation can divide into three types:
(1)
One to One Relation
(2)
One to Many Relation
(3)
Many to Many Relation
(1) One to One Relation:
A
row in a table, each associated with a row any at the other table, there is
known as One to One Relation.
(2) One to Many
Relation: A
row in a table, each associated with a many rows in at another table, there is
known as one to Many Relation.
(3) Many to Many
Relation: Many
rows create a table, each associated with a many rows in at another table, there
is known as many to Many Relation.
The
about three models called “degree of relationship”, which was developed by case
of mathematical concepts, these corners Relational Algebra in 1970's.
List of RDBMS Products:
There are most popular in RDBMS Product is:
-
SQL Server
-
Oracle
-
MySQL
-
DB2
- PostgreSQL
etc..
