Keywords: Uncertainty in data values is pervasive in all real-world environments and have received a lot of attention in the literature. Over the last decade or so, several extensions to the relational model have been proposed to address the issue of how data uncertainty can be modeled in a comprehensive manner. This chapter provides a summary of the major extensions. We discuss the strengths and weaknesses of these models and show the underlying similarities and differences. Data uncertainty, incomplete information, probabilistic database, relational algebra, query language 1.
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.