1 Goals of Data Warehousing 1. “The data warehouse must make an organization’s information easily accessible.” 2. “The data warehouse must present the organization’s information consistently.” 3. “The data warehouse must be adaptive and resilient to change.” 4. “The data warehouse must be a secure bastion that protects out information assets.” 5.“The data warehouse must serve as the foundation for improved decision making.” 6. “The business community must accept the data warehouse if it is to be deemed successful.” ETL Processes ETL is an acronym for a three-step process to extract data from source systems and load the data to a data warehouse. The three steps of the ETL process are: 1. Extract and load Staging Tables : Extracts and consolidates data from one or more source systems and loads into the data warehouse staging tables. 2. Transforms the data : Transforms data in the staging tables and computes calculated...
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•Planning, sales, and marketing organization data •Maintained in the form of: o Spreadsheets (structured) o Documents (unstructured) •Treated like any other source data Internal Data in Data warehouse
— Information from outside the organization —Issues of frequency, format, and predictability —Described and tracked using metadata External Data in Data warehouse
•Historical data •Useful for analysis over long periods of time •Useful for first-time load Archive Data in Data warehouse: