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Written by Roceller Alvarez
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Tuesday, 07 March 2006 |
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The ETL process involves mapping the data between source systems and target database such as data warehouse or data mart. The source data then goes through cleansing in the staging area. Then, the last step is transforming cleansed source data and then loading it into the target system.
Glossary of ETL (Source: Oracle.com):
Source System
A database, application, file, or other storage facility from which the data in a data warehouse is derived.
Mapping
The definition of the relationship and data flow between source and target objects.
Metadata
Data that describes data and other structures, such as objects, business rules, and processes. For example, the schema design of a data warehouse is typically stored in a repository as metadata, which is used to generate scripts used to build and populate the data warehouse. A repository contains metadata.
Staging Area
A place where data is processed before entering the warehouse.
Cleansing
The process of resolving inconsistencies and fixing the anomalies in source data, typically as part of the ETL process.
Transformation
The process of manipulating data. Any manipulation beyond copying is a transformation. Examples include cleansing, aggregating, and integrating data from multiple sources.
Transportation
The process of moving copied or transformed data from a source to a data warehouse.
Target System
A database, application, file, or other storage facility to which the "transformed source data" is loaded in a data warehouse.
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