a process data capture and reporting system captures process data values at sensors . a client computer appends absolute - value time stamps to the values to complete records , which are uploaded to a server . the server writes the records to a persistent database . at a later stage , the server retrieves selected records , and performs a very fast conversion of the time stamps to a calendar format with “ granular ” values for units such as day , month , or minute . the conversion is performed in an optimised manner with use of look - up tables in memory . this minimises processor overhead , and is thus very advantageous where data volumes are high and / or near real time reporting is required .