Abstract: XML is a markup language which is becoming the
standard format for information representation and data exchange. A
major purpose of XML is the explicit representation of the logical
structure of a document. Much research has been performed to
exploit logical structure of documents in information retrieval in
order to precisely extract user information need from large
collections of XML documents. In this paper, we describe an XML
information retrieval weighting scheme that tries to find the most
relevant elements in XML documents in response to a user query.
We present this weighting model for information retrieval systems
that utilize plausible inferences to infer the relevance of elements in
XML documents. We also add to this model the Dempster-Shafer
theory of evidence to express the uncertainty in plausible inferences
and Dempster-Shafer rule of combination to combine evidences
derived from different inferences.
Abstract: Main Memory Database systems (MMDB) store their
data in main physical memory and provide very high-speed access.
Conventional database systems are optimized for the particular
characteristics of disk storage mechanisms. Memory resident
systems, on the other hand, use different optimizations to structure
and organize data, as well as to make it reliable.
This paper provides a brief overview on MMDBs and one of the
memory resident systems named FastDB and compares the
processing time of this system with a typical disc resident database
based on the results of the implementation of TPC benchmarks
environment on both.