DSXchange

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.

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.

hi
i got it
but how to do in profile stage.
Thanks

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.

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?

I've moved this thread as it is more suitably discussed in the "Data Integration" forum.

Well i have the target tables deaigned and i do not have even a clue of what the transformation mappings are

This is actually a good task for MetaStage, particularly if good and wise practices have been used in DataStage design.

how will metastage help in this project. Isnt metastage used for metadata management.

You bet. And what are job designs and TX maps if not metadata?

Metastage will help with this great deal. You can actually see where the fields are coming from, how fields are geting built through its analyzers. I don't have the system available to me , but I was very impressed with this functionality during the training class.