Multiple keyword-based queries over XML streams

Abstract

In this paper, we propose that various keyword-based queries be processed over XML streams in a multi-query processing way. Our algorithms rely on parsing stacks designed for simultaneously matching terms from several distinct queries and use new query indexes to speed up search operations when processing a large number of queries. Besides defining a new problem and novel solutions, we perform experiments in which aspects related to performance and scalability are examined.

Keyword Search with Path-Based Filtering over XML Streams

“…Processing keyword search on static XML [6], [7] has been extensively studied before, and several works on XML stream [4]. CKStream [4] is an algorithm to process multiple keyword search over XML streams.…”

“…CKStream [4] is an algorithm to process multiple keyword search over XML streams. It relies on parsing stacks, query indexes, and query bitmap, specially designed to allow the simultaneous matching of terms from different queries.…”

“…We extend the NFA-based finite state machine in YFilter [3] by adding the data structures in CKStream [4], such as a set of used queries and query bitmap, thereby combining the keyword-search capability of CKStream and the pathbased filtering of YFilter. In addition, we use MLCA heuristic to generate query results because it gives more related and compact results than other heuristics [7].…”

“…On the other hand, keyword search [4], [7] provides a simple and effective query paradigm. However, there are some problems with keyword search.…”

“…More precisely, we extend NFA model to support XPath-based keyword search. We also extend NFA-based YFilter [3] with the method used in CKStream [4].…”