On representing interval measures by means of functions

Abstract

Multiple applications e.g., energy consumption meters, temperature or pressure sensors, generate series of discrete data. Such data have two characteristics, namely: they are naturally ordered by time and are frequently represented as intervals. Most of the research contributions, commercial software, or prototypes either (1) allow to analyze set oriented data, neglecting their order and duration or (2) represent intervals as discrete collection of points stored in tables. In this paper, based on our interval OLAP data model, we propose a method for representing interval data by means of functions and show that it is feasible to aggregate such data along hierarchical dimensions-in an OLAP-like style. To this end, we implemented a micro-prototype using Oracle PL/SQL. Its experimental evaluation showed that the concept is more space efficient and offers better performance than traditional approaches for some classes of analytical queries.