When I was browsing the net, looking for more information regarding federated-, decentralized – and centralized datawarehouses, I came across a great article by dr. Berg. Herewith a brief summary of his article.


Federated Data Warehouses are best in very large organization where development is separated by geography, organizational boundaries, or where multiple data warehouses exists due to mergers & acquisitions.

Federated Data Warehouses

Federated Data Warehouses

To make FDWs successful, there needs to be a rapid convergence to standardized technologies. This include:
  • Same type of databases and support pack levels (costs and compatibility)
  • Same technical platforms Hardware, Backups and Archiving (costs)
  • Shared Portal and user interface strategy (reduced training and support)
  • Shared security design and centralized administration (risk management)

If the data is federated you gain faster response time to business needs, can execute multiple projects in parallel, and work 24/7 across the globe. But without any standardization, it can also be very costly.


Centralized Data Warehouses are great for small and mid-size data warehouses (less than 15-40Tb). There are great benefits in terms of the ease to mange upgrades, support packs, enforcing development standards, transport control, master data management and the overall total cost of ownership. To make CDWs successful, there needs to be:

Centralized Data Warehouses
Centralized Data Warehouses
  • Adequate funding of hardware, application servers, database servers
  • Serious consideration should be made to move BI and reporting to BWA
  • Focus on using the database capacity on storage and data loads– not queries
  • No direct reporting from DSOs (takes too much system resources)
  • Broadcasting , caching and performance tuning is a dedicated support effort
  • A plan for data partitioning and archiving needs to be in-place as soon as the system exceeds 5-8 TB.

If the data is centralized it is faster to develop new solutions for the business and merging from different data sources are easier.


A Decentralized Data Warehouses makes sense if there are logical division between business units, geographies and little shared reporting. I.e. in a conglomerate organization with diverse business units. The benefits of DDWs include the flexibility of the FDW with the technology standardization and lower cost of ownership of the CDW. To make DDWs successful, there needs to be:

Decentralized Data Warehouses
Decentralized Data Warehouses
  • A formal Masterdata Management (MDM) strategy with clearly defined standards
  • A rule based data cleaning and data integration plan for centralized reporting
  • A shared hardware location to keep costs lower
  • Tight integration with upgrades, support packs and interface standards

With DDWs there is a risk of creating stove-pipe data marts that cannot be integrated at the corporate level without very high costs.