Faced with increasing demands for real-time data analysis, IT managers are cramming as much data as quickly as possible into their bulging data warehouses. In an address at last week's Data Warehousing Institute conference in Boston, IBM distinguished engineer Barry Devlin proposed a better approach: Maintain a core set of historical data in a data warehouse and build links to other data sources, including real-time data from transactional applications and unstructured data such as documents and images. Then, Devlin said, "You can stop trying to expand your data warehouse with all the data in the world."