Organizing Data
John Sum
Institute of Technology Management
National Chung Hsing University
2005 SPRING CSMU
Introduction to Information Management
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Data



Data
 A necessity for almost any enterprise to carry out its business.
Consists of raw facts, and when organized may be transformed
into information.
Database
 A collection of data organized to meet users’ needs
Database Management System (DBMS)
 A group of programs that manipulate the database and provide
an interface between the database and the user of the database
or other application programs.
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Introduction to Information Management
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The Hierarchy of Data
Database
A collection of integrated and
related tables.
Table
A collection of related records.
Record
A collection of related fields.
Field
A group of characters.
Character
Basic building block of information,
represented by a byte.
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Introduction to Information Management
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Data Entities, Attributes, and Keys
Entity
 A generalized class of people, places, or things
Entities
(objects) for which data is collected, stored,
Customer,
Employee
and maintained.
 Attribute
 A characteristics of an entity; something the
Attributes
entity is identified by.
Customer name,
Employee name Keys
 A field or set of fields in a record that is used to
identify the record.
Primary key
A field or set of fields that uniquely
identifies the record.
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Introduction to Information Management
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Keys and Attributes
Entities
(records)
Key Field
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Attributes
Introduction to Information Management
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The Traditional Approach
 The Traditional
Approach
 Separate files
are created
and stored for
each
application
program.
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Introduction to Information Management
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The Database Approach

The Database Approach
 A pool of related data is shared by multiple
application programs. Rather than having
separate data files, each application uses a
collection of data that is either joined or related in
the database.
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Introduction to Information Management
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The Database Approach
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Data Modeling and Database Models

Planned Data Redundancy

A way of organizing data in which the
logical database design is altered so that
certain data entities are combined.
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Summary totals are carried in the data records
rather than calculated from elemental data.
Some data attributes are repeated in more than
one data entity to improve database
performance.
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Data Modeling

Data Model
 A map or diagram of entities and their relationships.

Enterprise data modeling
 Data modeling done at the level of the entire organization.

Entity-Relationship (ER) diagrams
 A data model that uses basic graphical symbols to show
the organization of and relationships between data.
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Introduction to Information Management
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Entity Relationship (ER) Diagram
Attributes
Entities
Relationship
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Database Models

Hierarchical Database Model
 A data model in which the data is organized in a top-down,
or inverted tree structure.

Network Data Model
 An expansion of the hierarchical database model with an
owner-member relationship in which a member may have
many owners.

Relational Data Model
 All data elements are placed in two-dimensional tables,
called relations, that are the logical equivalent of files.
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Introduction to Information Management
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Hierarchical Database Model
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A Network Data Model
Owners
Members
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A Relational Data Model
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Introduction to Information Management
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Relational Database Terms

Selecting
 Data manipulation that eliminates rows according to
certain criteria.

Projecting
 Data manipulation that eliminates columns in a table.

Joining
 Data manipulation that combines two or more tables.

Linked
 Related tables in a relational database together.
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Introduction to Information Management
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Linking Data Tables to Answer an Inquiry
Description
Dept. Number
Sales Manual 598
2005 SPRING CSMU
Manager SSN
098-40-1370
Lastname
Fiske
Introduction to Information Management
Hiredate
01-05-1985
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Logical and Physical Access Paths
Logical Access Path
Application requires
information from the DBMS.
Physical Access Path
DBMS accesses a storage device
to retrieve data.
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Introduction to Information Management
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Manipulating Data

Concurrency Control
 A method of dealing with a situation in which two or more
people need to access the same record in a database at
the same time.

Data Manipulation Language (DML)
 The commands that are used to manipulate the data in a
database.

Structured Query Language (SQL)
 A standardized data manipulation language.
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Introduction to Information Management
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Structured Query Language
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Introduction to Information Management
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Database Output
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Popular DBMS

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Microsoft Access
Lotus Approach
Orcale
IBM DB2
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DBMS Selection Criteria
Database size
Number of concurrent users
Performance
Integration
Features
The vendor
Cost
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Distributed Databases

A database in which the actual data may be
spread across several smaller databases
connected via telecommunications devices.
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Introduction to Information Management
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Distributed Databases
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Open Database Connectivity (ODBC)

A set of standards that
ensures software
written to comply with
these standards can be
used with any ODBCcompliant database.
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Introduction to Information Management
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Data Mining

The automated discovery of
patterns and relationships in a data
warehouse.
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