1. A computer-implemented method for displaying a visual representation of data on a screen, comprising: receiving a first set of data from a first data source, the first set of data having data entries, each data entry being associated with a different time of a first time interval; keying data entries of the first set of data, each keyed data entry being associated with a different count-based index; storing the keyed data entries; retrieving two or more of the keyed data entries using the count-based indices, and summarizing those two or more of the retrieved data entries for the first set of data received over a predetermined time interval to generate a first pre-processed datum representing a summarized datum for the first data source over the predetermined time interval, the predetermined time interval being shorter than the first time interval; storing the first pre-processed datum in data storage; retrieving the first pre-processed datum responsive to receiving a request for the first set of data covering the predetermined time interval; and displaying a visual representation of the first set of data on the screen based on the first pre-processed datum responsive to retrieving the first pre-processed datum.