Lately, there's been lots of buzz around the logical data warehouse (LDW). In fact, Gartner is hearing LDW mentions as part of data warehouse (DW) inquiries almost 20% of the time and considers it a "megatrend." The definition usually includes some use of data virtualization or data federation capabilities to complement an existing DW repository to allow access to the data without having to move it.

While data federation is only one component of building a logical data warehouse and adopting a data virtualization strategy, it is a concrete way to deliver value to the business using a phased approach that augments governance and security.

SAS Federation Server provides an abstraction layer that helps business users view data without knowing (or caring) that the data might have come from joining data between a marketing datamart stored in Oracle, web-browser data stored in a Teradata or Hadoop cluster, and an Excel file containing demographic information. This improves "business user usability" by using business-friendly terms instead of mainframe field names. It means there's less demand on constricted IT resources without having to create yet another datamart or take yet another phone call explaining what a term means.

A business user might, for example, be using a visualization tool like SAS Visual Analytics and need to query a combination of resources to create a sales report or conduct forecasting. A request can be made of IT without IT having to provision a new datamart; they need only create a "federated view" of the data joined across multiple sources like the DW or master data management solution, optionally using a caching mechanism to speed access to the data. They can reduce costs here by caching mainframe DB2 data for often repeated queries inside a SQL server or Oracle engine with lower chargebacks, for example. They can also take advantage of push-down capabilities in the databases and perform subquery optimization to ensure that the request is conducting as much processing at the database level as possible before viewing the data.

Going one step further, "database-savvy" business users can create very simple joins between the federated view and some other data source they have access to using the SAS Visual Analytics Visual Data Builder, a web-based lightweight tool created for this purpose. (In future versions of SAS Federation Server, a capability like this may be brought into the Federation Server to further empower the business user and reduce IT constraints.)

Data federation thus simplifies business user access to the data, reduces costs of accessing data, delivers better query performance via caching and provides a security and governance layer over who is accessing what data. No wonder it's a megatrend!