Database Reference
In-Depth Information
Chapter 7
Fuzzy Querying Capability
at Core of a RDBMS
Ana Aguilera
Universidad de Carabobo, Venezuela
José Tomás Cadenas
Universidad Simón Bolívar, Venezuela
Leonid Tineo
Universidad Simón Bolívar, Venezuela
ABSTRACT
This chapter is focused in incorporating the fuzzy capabilities to a relational database management system
(RDBMS) of open source. The fuzzy capabilities include connectors, modifiers, comparators, quantifiers,
and queries. The extensions consider a more flexible DDL and DML languages. The aim is to show the
design and implementation details in the RDBMS PostgreSQL. For this, a fuzzy query processor and
fuzzy access mechanism has been designed and implemented. The physical fuzzy relational operators
have been also defined and implemented. The flow of a fuzzy query through the different modules (parser,
planner, optimizer, and executor) has been shown. Some experimental results have been included to
demonstrate the performance of the proposal solution. These results show that the extensions have not
decreased the performance of the RDBMS.
INTRODUCTION
The language used by human beings is imprecise, but for the computer the opposite stands true. Scientists
are continually investigating how to create an intermediate point to enhance the communication between
these different worlds. Moreover, the capacity to store large quantities of data is growing in an exponen-
