Data Warehouse Source Analysis Oracle Tips by Burleson Consulting

The Data Warehouse Development Life Cycle

Data Warehouse Source Analysis

In this phase of warehouse analysis, developers identify end user data requirements and legacy data sources. This process begins by understanding the types of queries that the end user community desires from their new database. Data source analysis always begins by soliciting the data warehouse user community. Unlike other systems where the end-users may be semi-skilled workers, the end-users of a data warehouse are generally highly trained statisticians whose job is to identify and exploit trends within their functional area. Examples of this type of end-users would be Financial manager, and Marketing analysts. It is only by interrogating the end users that the data warehouse analyst can understand how source data will be captured from external systems. Remember, a data warehouse always begins as a tabula rasa, and the data is loaded and transformed from numerous external sources.

ANALYZING SOURCE DOCUMENT INPUT

Because the data for a data warehouse already exists in a database, it is very tempting for the data warehouse analyst to gloss over an analysis of the source documents for the organization. However, a thorough source document analysis will provide insight into both the internal structure of the data as well as management’s uses for the data. Consequently, we will begin with the first step in data analysis for a data warehouse--analyzing the source documents that comprise the values in the existing OLTP databases.

To review basic systems analysis, you need to be familiar with the following notations used to describe values in the data dictionary:

* Optional Item--An item that is not required is placed in parenthesis. Optional items are any data items that may exist in the Oracle database with a null value. For example:

customer_date = name, (age), address, (social_security_number)

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This is an excerpt from "High Performance Data Warehousing", copyright 1997.

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