2. Data vs. InformationData vs. Information
• Data
• Raw facts; building blocks of information
• Unprocessed information.
• Information:
• Data processed to reveal meaning
Accurate, relevant, and timely information is key to good decision making.
Good decision making is the key to survival in a global environment.
3. Database (DB)Database (DB)
• A database is a collection of information that is organized so that it can be easily
accessed, managed and updated.
• Data is organized into rows, columns and tables, and it is indexed to make it easier to find
relevant information.
• Data gets updated, expanded and deleted as new information is added.
• Databases process workloads to create and update themselves, querying the data they
contain and running applications against it.
4. Database Management SystemDatabase Management System
• A Database Management System (DBMS) is a computer software application that
interacts with the user, other applications, and the database itself to capture and analyze
data. A general-purpose DBMS is designed to allow the definition, creation, querying,
update, and administration of databases
5. Advantage of DBMSAdvantage of DBMS
Improved data sharing.
Improved data security.
Better data integration.
Minimized data inconsistency.
Improved data access.
Improved decision making.
Increased end-user productivity.
6. Disadvantage of DBMSDisadvantage of DBMS
• Increased costs
• Management complexity
• Maintaining currency
• Frequent upgrade/replacement cycles
9. WorkgroupWorkgroup
Supports multiple users at the same time
Workgroup: Multi-user database that supports a small group of users or a single department
Enterprise: Multi-user database that supports a large group of users or an entire organization
13. Data warehouseData warehouse
• Stores data used to generate information required to make tactical or strategic decisions
• Often used to store historical data
• Structure is quite different
15. MySQLMySQL
• MySQL is a very popular, open source database.
• Officially pronounced “my Ess Que Ell” (not my sequel).
• Handles very large databases; very fast performance.
• Why are we using MySQL?
• Free (much cheaper than Oracle!)
• Each student can install MySQL locally.
• Easy to use Shell for creating tables, querying tables, etc.
16. MySQL IntroductionMySQL Introduction
• MySQL is a database management system
• SQL stands for the Structured Query Language. It defines how to
insert, retrieve, modify and delete data
• Free from www.mysql.com
• Reference sites
• NASA, Yahoo!, Compaq, Motorola, Facebook
17. DATABASE MODELDATABASE MODEL
A database model is a type of data model that determines the logical
structure of a database and fundamentally determines in which manner
data can be stored, organized, and manipulated.
18. The Evolution of DatabaseThe Evolution of Database
From pre-stage flat-file system, to relational and object-relational
systems, database technology has gone through several generations and
its history that is spread over more than 40 years now.
19. Flat FilesFlat Files
• 1968 File-Based: predecessor of database, Data was maintained in a flat file.
• Earlier, punched cards technology was used to store data – later, files. But the
files have no as such advantage, rather have several limitations.
21. DATABASE MODELSDATABASE MODELS
Database management systems are usually categorized according to the data model.
Common models include:
1.Hierarchical model
2.Network model
3.Relational model
4.Entity-Relationship model
5.Object model
6.Object-relational model
22. Hierarchical ModelHierarchical Model
In mid 1960s, Rockwell partnered with IBM - create Information
Management System (IMS). IMS lead the mainframe database market in
70’s and early 80’s. Hierarchical data model.
23. Hierarchical data modelHierarchical data model
• In a Hierarchical model, data is organized into a tree-like structure, implying a single
parent for each record. A sort field keeps sibling records in a particular order.
• Hierarchical structures were widely used in the early mainframe database management
systems, such as the Information Management System (IMS) by IBM, and now describe the
structure of XML documents.
• This structure allows one one-to-many relationship between two types of data. This
structure is very efficient to describe many relationships in the real world; recipes, table of
contents, ordering of paragraphs/verses, any nested and sorted information.
25. AdvantagesAdvantages
•Less redundant data.
•Data independence.
•Database security and integrity
LimitationsLimitations
•Complex implementation
•Difficult to manage and lack of standards, can’t easily handle many-many relationships.
•Lacks structural independence.
26. Network ModelNetwork Model
Early 1960s, Charles Bachmann developed first DBMS at Honeywell, Integrated Data
Store (IDS).
Network data model identified the following three database components:
•Network schema—database organization[structure]
•Sub-schema—view s of database per user
•Data management language — at low level , procedural
•Later 1971 standardized by the CODASYL (Conference on Data Systems Language)
27. Network ModelNetwork Model
The Network model expands upon the hierarchical structure, allowing many-to-many relationships in
a tree-like structure that allows multiple parents. It was most popular before being replaced by the
relational model, and is defined by the CODASYL specification.
The network model organizes data using two fundamental concepts, called records and sets. Records
contain fields (which may be organized hierarchically, as in the programming language COBOL).
Sets (not to be confused with mathematical sets) define one-to-many relationships between records:
one owner, many members. A record may be an owner in any number of sets, and a member in any
number of sets.
29. AdvantagesAdvantages
•Ability to handle more relationship types
•Ease of data access
•Data Integrity
•Data Independence
LimitationsLimitations
•System complexity and difficult to design and maintain
•Lack of structural independence as data access method is navigational.
30. Relational ModelRelational Model
1970s, E.F. Codd, an IBM researcher
•Disconnected the schema (logical organization) of a database
from the physical storage methods.
•First successful database product for microcomputers was
dBASE
•The term Relational Database Management System
(RDBMS) was introduced during this period
31. Relational ModelRelational Model
A database based on the relational model developed by E.F. Codd. A relational database allows the
definition of data structures, storage and retrieval operations and integrity constraints. In such a
database the data and relations between them are organized in tables. A table is a collection of
records and each record in a table contains the same fields.
Properties of Relational Tables:
Values Are Atomic
Each Row is Unique
Column Values Are of the Same Kind
The Sequence of Columns is Insignificant
The Sequence of Rows is Insignificant
Each Column Has a Unique Name
33. Entity-Relationship (ER) modelEntity-Relationship (ER) model
In 1976, Dr. Peter Chen
•The entity-relationship model (or ER model) is a way of
graphically representing the logical relationships of
entities (or objects) in order to create a database.
35. Object-Oriented ModelObject-Oriented Model
1985 - Object-Oriented model
Object oriented databases are also called Object Database Management Systems (ODBMS).
Object databases store objects rather than data such as integers, strings or real numbers.
Objects are used in object oriented languages such as Smalltalk, C++, Java, and others.
Objects basically consist of the following:
Attributes - Attributes are data which defines the characteristics of an object. This data may
be simple such as integers, strings, and real numbers or it may be a reference to a complex
object.
Methods - Methods define the behavior of an object and are what was formally called
procedures or functions.
36. Object-oriented Relational modelObject-oriented Relational model
1990s - Object-oriented Relational model
Object-oriented models are very powerful but also quite complex. With the relatively
new object-relational database model is the wide spread and simple relational database
model extended by some basic object-oriented concepts. These allow us to work with
the widely know relational database model but also have some advantages of the
object-oriented model without its complexity.
37. The database system can be divided intoThe database system can be divided into
four components.four components.
Users : Users may be of various type such as DB
administrator, System developer and End users.
Database application : Database application may be
Personal, Departmental, Enterprise and Internal.
DBMS : Software that allow users to define, create and
manages database access, Ex: MySQL, Oracle etc.
Database : Collection of logical data.
