03-11-2016, 03:53 PM
1464160878-krithitalkimpact.ppt (Size: 1.39 MB / Downloads: 31)
What is a Data Warehouse?
A single, complete and consistent store of data obtained from a variety of different sources made available to end users in a what they can understand and use in a business context.
What are the users saying...
Data should be integrated across the enterprise
Summary data has a real value to the organization
Historical data holds the key to understanding data over time
What-if capabilities are required
What is Data Warehousing?
A process of transforming data into information and making it available to users in a timely enough manner to make a difference
Evolution
60’s: Batch reports
hard to find and analyze information
inflexible and expensive, reprogram every new request
70’s: Terminal-based DSS and EIS (executive information systems)
still inflexible, not integrated with desktop tools
80’s: Desktop data access and analysis tools
query tools, spreadsheets, GUIs
easier to use, but only access operational databases
90’s: Data warehousing with integrated OLAP engines and tools
Data Warehousing -- It is a process
Technique for assembling and managing data from various sources for the purpose of answering business questions. Thus making decisions that were not previous possible
A decision support database maintained separately from the organization’s operational database
Data Warehouse
A data warehouse is a
subject-oriented
integrated
time-varying
non-volatile
collection of data that is used primarily in organizational decision making.
-- Bill Inmon, Building the Data Warehouse 1996