HISTORY OF DATA WAREHOUSING
*In 1990s organization began to need more timely information about their business that traditional operational information system.
*Operational system including accounting,order entry and sales are not appropriate for business analysis for the following reasons :
- Information from other operational applications is not included.
- Operational systems are not integrated
- Operational information is mainly current-does not include the history for better decision making
- Operational information frequently has quality issues(errors)-information need to be cleansed.
- Without information history, it is difficult to tell how and why things change over time.
DATA WAREHOUSE– a logical collection of
information – gathered from many different operational databases – that
supports business analysis activities and decision-making tasks.
~PURPOSE-to aggregate information throughout an organization into a single repository in such a way that employees can make decision and undertake business analysis activities.
EXTRACTION,TRANSFORMATION AND LOADING(ETL)
DATA WAREHOUSE MODEL
MULTIDIMENSIONAL ANALYSIS AND DATA MINING
Relational Database contain
information in a series of two-dimensional tables.
In a data warehouse and data mart, information is
multidimensional, it contains layers of columns and rows
- Dimension – a particular attribute of information.
CUBE–
common term for the representation of multidimensional information
DATA MINING
The process of analyzing data to extract information not
offered by the raw data alone. Also begin at summary information level (coarse
granularity) and progress through increasing levels of details (drilling down)
or the reverse(drilling up) and to perform this uses need data-mining tools.
DATA-MINING TOOLS
Uses a variety of techniques to find patterns and
relationships in large volumes of information. Eg: retailers can use knowledge
of these patterns to improve the placement of items in the layout of a
mail-order catalog page or Web page.
An organization must maintain high-quality data in the data
warehouse
INFORMATION
CLEANSING OR SCRUBBING– a process that weeds out and fixes or
discards inconsistent, incorrect, or incomplete information
In data warehouse information cleansing occur during ETL
process and second on the information once if is in the data warehouse.
Contact information in an operational system
Standardizing Customer name from Operational Systems
Information cleansing activities
Accurate and complete information
Refers to applications and
technologies that are used to gather, provide access, analyze data, and
information to support decision making effort.
These systems will illustrate
business intelligence in the areas of customer profiling, customer support,
market research, market segmentation, product profitability, statistical analysis,
and inventory and distribution analysis to name a few
Eg: Excel, Access
ENABLING BUSINESS INTELLIGENCE
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