Lesson 1 Flashcards
Organized collection of logically
related data.
Database
Stored representations of
meaningful objects and events.
Data
Examples of this type of data are numbers, text, and dates
Structured Data
Examples of this type of data images, video, documents
Unstructured Data
Data processed to increase
knowledge of the person using the
data.
Information
Data that describes the properties
and context of user data.
Metadata
It helps users understand
data.
Context (Data in Context)
This turns data into
useful information that managers
can use for decision making and
interpretation.
Graphical Displays
Descriptions of the properties or
characteristics of the data, including data types, field sizes, allowable values, and data context.
Metadata and Constraints
Data that describe the properties or
characteristics of end-user data and
the context of that data.
Metadata
Describing the properties that are
typically described include data
names, definitions, length (or size,
and allowable values.
Metadata (2)
Describing data context include the
source of the data, where the data
are stored, ownership (or
stewardship), and usage.
Metadata (3)
Disadvantages of File Processing
- Program-Data Dependence
- Duplication of Data
- Limited Data Sharing
- Lengthy Development Times
- Excessive Program Maintenance
All programs maintain metadata for each file they use.
Program-Data Dependence
Different systems/programs have separate copies of the same data.
Duplication of Data
No centralized control of data.
Limited Data Sharing
Programmers must design their own file
formats.
Lengthy Development Times
80% of information systems budget.
Excessive Program Maintenance
Problem with Data Dependency
- Each application programmer must
maintain his/her own data. - Each application program needs to
include code for the metadata of each
file. - Each application program must have its
own processing routines for reading,
inserting, updating, and deleting data. - Lack of coordination and central control.
- Non-standard file formats.
Problem with Data Redundancy
● Waste of space to have duplicate data.
● Causes more maintenance headaches.
● The biggest problem:
○ Data changes in one file could cause
inconsistencies.
○ Compromises in data integrity.
The Database Approach
- Central Repository of shared data.
- Data is managed by a controlling
agent. - Stored in a standardized, convenient
form.
A software system that is used to
create, maintain, and provide
controlled access to user databases.
It is a set of software tools that
control access, organize, store,
manage, retrieve and maintain data
in a database.
Database Management System (DBMS)
Program-data independence
Advantages of Database Approach
Planned data redundancy
Advantages of Database Approach
Improved data consistency
Advantages of Database Approach
Improved data sharing
Advantages of Database Approach
Increased application development
productivity
Advantages of Database Approach
Enforcement of standards
Advantages of Database Approach
Improved data quality
Advantages of Database Approach
Improved data accessibility and
responsiveness
Advantages of Database Approach
Reduced program maintenance
Advantages of Database Approach
Improved decision support
Advantages of Database Approach
New, specialized personnel.
Costs and Risks of Database Approach
Installation and management cost
and complexity.
Costs and Risks of Database Approach
Conversion costs.
Costs and Risks of Database Approach
Need for explicit backup and
recovery.
Costs and Risks of Database Approach
Organizational conflict on data
definitions, formats and coding, and
rights to update.
Costs and Risks of Database Approach
