The document discusses data warehousing and its benefits and challenges. It defines a data warehouse as a subject oriented, integrated, time-variant, and nonvolatile collection of data used to support management decision making. It notes that data warehousing supports reporting and analysis and can provide benefits like high returns on investment, competitive advantage, and increased productivity. However, it also discusses challenges like underestimating resource needs, data integration issues, and changing user demands. The document also outlines the typical architecture of a data warehouse system.

1. Advanced Database Systems
What is Data Warehousing?
A data warehouse can be defined as
follows:
subject oriented
integrated
time-variant
nonvolatile
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Data Warehousing
It is a collection of data in support of
management decision-making process.

2. Advanced Database Systems
Benefits of
Data Warehousing
Data warehousing is intended to support
reporting and analysis of data.
Here are the benefits as follows:
Potential High Returns on Investment
Competitive Advantage
Increased Productivity of Corporate
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Data Warehousing
Increased Productivity of Corporate
Decision Makers

3. Advanced Database Systems
Problems of Data
Warehousing
Here are some problems associated with
developing and maintaining a data
warehouse as follows:
Underestimation of Resources for Data
Loading
Hidden Problems with Source Systems
Required Data not Captured
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Data Warehousing
Required Data not Captured
Increased End User Demands
Data Homogenization
High Demand for Resources
Data Ownership
High Maintenance
Long Duration Projects
Complexity of Integration

4. Advanced Database Systems
Data Warehouse
Architecture
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Data Warehousing

5. Advanced Database Systems
Data Warehouse
Architecture
Operational Data Store
A repository of current and integrated
operational data used for analysis
Load Manager
Performs all the operations associated with
the extraction and loading of data into the
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Data Warehousing
the extraction and loading of data into the
warehouse

6. Advanced Database Systems
Data Warehouse
Architecture
Warehouse Manager
Performs all the operations associated with
the management of data in the warehouse
Query Manager
Performs all the operations associated with
the management of user queries
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Data Warehousing
the management of user queries

7. Advanced Database Systems
Data Warehouse
Architecture
Detailed Data
The area of the warehouse which stores all
the detailed data in the database schema
Lightly and Highly Summarized Data
The area of the warehouse which stores all
the predefined lightly and highly
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Data Warehousing
the predefined lightly and highly
summarized data generated by the
warehouse manager

8. Advanced Database Systems
Data Warehouse
Architecture
Archive/Backup Data
The area of the warehouse where detailed
and summarized data are stored for the
purpose of archiving and backup
Metadata
The area of the warehouse where all the
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Data Warehousing
The area of the warehouse where all the
metadata (data about data) definitions are
stored
End-User Access Tools
These tools are used to interact with the
data warehouse to obtain information