Today, technologies are rapidly converging to enable the next leap forward in data warehousing - the ability to affordably keep all business data accessible to the data warehouse - forever.

Regulatory and legal retention requirements are leading businesses to keep years and years of historical data accessible in the data warehouse. Cost reductions in paper-based records and mail delivery are motivating businesses to keep many years of historical business records, account records, and customer statements online and accessible.

This large, growing amount of data in a data warehouse has different temperatures because data temperature varies with time. The average temperature of data tends to cool off over time. There are temperature fluctuations or hot spots as periodic analysis is performed, such as current quarter analysis versus same quarter last year. Data temperature is a function of the access rate for queries, updates, and data maintenance (e.g., data model change, statistics gathering, and integrity checking). Usually there's a correlation between data volume and temperature, with more cool data than warm and hot data.