What is Data Warehouse ? Is there any guide document to use it?

DataWarehouse is a repository of SiteCatalyst data that stores information similar to that which you can see in SiteCatalyst. DWH is only a backup of their data, it is actually much more than that. To understand DataWarehouse, you need to first understand how it differs from SiteCatalyst.

Go thro this link, http://blogs.adobe.com/digitalmarketing/analytics/omniture-datawarehouse-inside-omniture-sitecatalyst/

[img]DWH Overview.jpg[/img]

If you want to use DWH, please refer this link to get detailed solutions,

https://marketing.adobe.com/developer/get-started/enterprise-api/c-data-warehouse-overview

Hope this helps!