Management of sparse data for database systems with multiple processing units

The number of processors that store data can be limited for some data in order to improve efficiency in database system that uses multiple processing units to process data. For example, a map can be provided for one or more sparse database tables (or tables) that are relatively small in view of the number of processors that are available. The map can effectively assign distinct portions of the data, e.g., rows of a database, for processing only to a limited number of processors (or processing units). The database system can use the map to process data accordingly.