1. A method for managing multiple subsets of data stored in a database, comprising: storing a superset of sampling data as a plurality of data records, said superset including a plurality of sampling interval data sets, each sampling interval data set including sampling data corresponding to a first time interval of a first time length where said superset includes sampling data for a plurality of sequential time intervals; sampling data in said superset over a second time interval of a second time length which is a multiple of said first time length to generate information identifying a subset of data for said superset, wherein said sampling creates a second sampling level associated with said identified subset of data wherein said second sampling level includes a plurality of second time intervals; sampling said data of said identified subset of data over a third time interval of a third time length which is a multiple of said second time length to generate information identifying a second subset of data from said superset; and assigning a code to each record in the superset wherein said code identifies the highest sampling level with which said record is associated.