Aggregating high volumes of temporal data from multiple overlapping sources

There is provided a method and associated system that allows for aggregating high volumes of temporal data from multiple overlapping sources to allow data availability without query degradation. The method includes (1) receiving a data element, (2) comparing the data element to a corresponding data element in a pend update history repository that contains changes that have occurred to the data element over time, thus yielding a comparison, (3) determining, based on the comparison, that the data element has changed, (4) checking that there is no update process running that might contain more up-to-date data for the data element, (5) relating the data element to a cutoff number that is associated with a particular range of time, and (6) updating corresponding data elements in (a) a full universe data repository that stores a current value for the data element and a previous value for the data element, and (b) a delta data repository that stores a record that indicates (i) that the data element is being updated, and (ii) the cutoff number.