Efficient Evaluation of Logical Expressions Defined on XML Streaming Data
Speaker: Belinda Carter, ITEE
When: 2005-11-29 09:00:00
Venue: 78-420
Host: Dr Shazia Sadiq
Abstract:XML has rapidly become a dominant standard for data exchange between
heterogeneous systems and its adoption in applications such as
e-commerce is driving the need for rule-based technology to support
reactive functionality on XML repositories. As in traditional
relational database systems, each rule consists of a condition and
an associated action that must be executed whenever the condition
over the XML database holds. The conditions can be defined as
logical expressions involving the content of one or more XML
documents.
The motivation for this work is the increasing use of XML message
exchange in the facilitation of business processes that are defined
through a set of rules where hundreds of independent instances of
the same process are asynchronously being executed. In such
applications, each condition expression may be dependent on the
receipt of multiple XML documents and each such document may
contribute towards the evaluation of multiple expressions in
different ways. Due to the unpredictable order of the events
(arrival of messages) contributing towards the evaluation of these
complex expressions and the long durations over which such processes
typically execute, thousands of expressions may be in a state of
øpartial evaluationù at any given time. However, real-time response
is a requirement of supporting systems.
The deployment of reactive XML repositories for large-scale web
applications therefore raises issues about the performance and
scalability of the underlying system. We intend to address these
issues in this project. We introduce a formalism for the definition
of condition expressions and present a discussion on the evaluation
of such expressions in an intensive environment. We then present
questions to be addressed as future work and a plan for this
research.
Biography:(biography unavailable)
Type: Ph.D Confirmation
Contact:Dr Shazia Sadiq, seminar host (shazia@itee.uq.edu.au)
or Guido Governatori (ITEE seminar co-ordinator)
(guido@itee.uq.edu.au)