Patent ID: 7720806

Claim:
A computer system implemented method for providing a requested data set, the computer system comprising at least one processor, memory and a data store, the method comprising: providing a relation store in the memory; storing a plurality of data sets in the data store, including at least a first data set and a second data set, wherein the date store includes a volatile memory and a non-volatile storage medium and wherein the first data set and the second data set contain the same logical data stored in different physical formats, the first data set being stored in a first physical format having a first size and the second data set being stored in a second physical format having a second size that is smaller than the first size; composing at least two alternative algebraic relations that each define a result equal to the requested data set, including a first algebraic relation based on at least the first data set stored in the data store and a second algebraic relation based on at least the second data set stored in the data store, wherein the first algebraic relation and the second algebraic relation each comprise a respective first expression including a symbolic representation of at least a first respective data set, a respective second expression including a symbolic representation of at least a second respective data set; and a relational operator symbolically defining a mathematical relationship between the respective first expression and the respective second expression; storing the first algebraic relation and the second algebraic relation in the relation store; determining that the first data set is available in the volatile memory; and selecting the first algebraic relation to calculate the requested data set.