Evaluating Probabilistic Queries over Imprecise Data

Many applications employ sensors for monitoring entities such as temperature and wind speed. A centralized database tracks these entities to enable query processing. Due to continuous changes in these values and limited resources (e.g., network bandwidth and battery power), it is often infeasible to store the exact values at all times. A similar situation exists for moving object environments that track the constantly changing locations of objects. In this environment, it is possible for database queries to produce incorrect or invalid results based upon old data. However, if the degree of error (or uncertainty) between the actual value and the database value is controlled, we can place more confidence in the answers to queries. More generally, query answers can be augmented with probabilistic estimates of the validity of the answers. In this chapter we study probabilistic query evaluation based upon uncertain data. A classification of queries is made based upon the nature of the resu...

• Type: Conference
• Year: 2003
• Where: SIGMOD
• Authors: Reynold Cheng, Dmitri V. Kalashnikov, Sunil Prabhakar
• Keywords: Database, Database Queries, Probabilistic Answers, Probabilistic Query Evaluation, SIGMOD 2003