Missing maps in datawarehouse
Missing maps in datawarehouse
HI
This is a real time problem. I have datawarehouse built. I dont have mapping from source to target. The documentation is lost. I want to know how to relate a source column to target column.
This is a real time problem. I have datawarehouse built. I dont have mapping from source to target. The documentation is lost. I want to know how to relate a source column to target column.
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You are in a row boat that is leaking badly, you are miles from land and you have been given a tea spoon to bail with.
Have your ETL jobs already been built (and you are trying to reverse engineer the mapping documentation) or are you about to start building them? Are there any functional documents such as business requirements? Are any of the people who did the original documentation still available (either technical staff or business analysts). How much time do you have?
Assuming you have no time and no resources there is an express mode or a slow mode. Express mode is to bring ProfileStage in, profile your sources, profile your target and let ProfileStage build the mapping jobs for you. Slow mode is to rewrite the source to target maps following the normal DW processes with input from the people who know the business requirements and business rules.
Either way you really need some input from people who know the business requirements otherwise you will make a lot of mistakes.
Have your ETL jobs already been built (and you are trying to reverse engineer the mapping documentation) or are you about to start building them? Are there any functional documents such as business requirements? Are any of the people who did the original documentation still available (either technical staff or business analysts). How much time do you have?
Assuming you have no time and no resources there is an express mode or a slow mode. Express mode is to bring ProfileStage in, profile your sources, profile your target and let ProfileStage build the mapping jobs for you. Slow mode is to rewrite the source to target maps following the normal DW processes with input from the people who know the business requirements and business rules.
Either way you really need some input from people who know the business requirements otherwise you will make a lot of mistakes.
Certus Solutions
Blog: Tooling Around in the InfoSphere
Twitter: @vmcburney
LinkedIn:Vincent McBurney LinkedIn
Blog: Tooling Around in the InfoSphere
Twitter: @vmcburney
LinkedIn:Vincent McBurney LinkedIn
This is exactly why I wrote DwNav. I use it to help me understand the ETL created by previous consultants. That was the main reason for writing it. Most of the time you do not have access to these people. What I found was most of the time you need just source and target tables. DwNav can browse these in the tool or generate html documentation to do it.
Very inexpensive tool. Pay for itself first time you need it for something like this but do it the hard way like most developers. Make a man out of you.
Very inexpensive tool. Pay for itself first time you need it for something like this but do it the hard way like most developers. Make a man out of you.
Mamu Kim
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Let me repeat the question. Do you already have ETL jobs built and you are trying to document them or are in you in the process of building the ETL jobs?
Certus Solutions
Blog: Tooling Around in the InfoSphere
Twitter: @vmcburney
LinkedIn:Vincent McBurney LinkedIn
Blog: Tooling Around in the InfoSphere
Twitter: @vmcburney
LinkedIn:Vincent McBurney LinkedIn
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