A data-intensive computer includes a processing sub-system formed by a plurality of processing servers, a database sub-system formed by a plurality of database servers configured to form a collective database, and a unifying operating system environment. The unifying operating system environment extends across the processing sub-system and the database sub-system to coordinate operation of the plurality of processing servers and the plurality of database servers to act as components in a single data-intensive computer and presents the database sub-system to an application running in the data-intensive computer as a layer in a memory hierarchy of the data-intensive computer.