RANDOM DATA STREAM SAMPLING

摘要

There is provided a method of sampling data elements from a data stream for subsequent analysis, the data stream comprising a plurality of data elements, wherein each data element has a respective unique quasi-random identifier determined from a set of identifiers, the method comprising selecting data elements from the data stream whose identifiers are within a first element selection range to give a set of selected data elements, the first element selection range being a subset of the set of identifiers; wherein, once the set of selected data elements comprises a predetermined number of data elements, the method further comprises: determining a second element selection range as a proper subset of the first element selection range; discarding data elements from the set of selected data elements whose identifiers are not within the second element selection range; and selecting at least one further data element from the data stream whose identifier is within the second element selection range for the set of selected data elements.