Patent attributes
Data objects are sampled from data sources and stored in a tree data structure that is employed to compute histogram information. Each node in the tree includes sufficient statistics and a particular value corresponding to one or more sampled data objects. The nodes of the tree can be two or more types, such as exponential nodes and regular nodes. Also, each histogram tree may be precalculated to start with an empty exponential node, and a defined number of regular nested nodes that correlate to a precision value for the histogram, i.e., a number of significant figures for sampled data values that can be stored in the tree.