Praveen R. Rao

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We propose a new way of indexing XML documents and processing twig patterns in an XML database. Every XML document in the database can be transformed into a sequence of labels by Prufer's method that constructs a one-to-one correspondence between trees and sequences. During query processing, a twig pattern is also transformed into its Prufer sequence. By(More)
In recent years, publish-subscribe (pub-sub) systems based on XML document filtering have received much attention. In a typical pubsub system, subscribed users specify their interest in profiles expressed in the XPath language, and each new content is matched against the user profiles so that the content is delivered to only the interested subscribers. As(More)
We propose a new way of indexing XML documents and processing twig patterns in an XML database. Every XML document in the database can be transformed into a sequence of labels by prüfer's method that constructs a one-to-one correspondence between trees and sequences. During query processing, a twig pattern is also transformed into its Prüfer(More)
One of the key challenges in a peer-to-peer (P2P) network is to efficiently locate relevant data sources across a large number of participating peers. With the increasing popularity of the extensible markup language (XML) as a standard for information interchange on the Internet, XML is commonly used as an underlying data model for P2P applications to deal(More)
In recent years, there has been a growing interest for peer-to-peer (P2P) based computing and applications. One of the most important challenges in P2P environments is to quickly locate relevant data across many participating peers. In this demonstration, we present psiX, which is an Internet-scale service for publishing and locating XML documents. This(More)
In recent years, publish–subscribe systems based on XML filtering have received much attention in ubiquitous computing environments and Internet applications. The main challenge is to process a large number of content against millions of user subscriptions. Several XML filtering systems focus on the efficient processing of structural matching of user(More)
In recent years, there has been a rising interest in developing online approximation algorithms for data streams. Some of the key challenges are posed by the fact that streaming data can be read only once in a fixed order of arrival and only a limited amount of memory is available for storage. In this paper, we address the problem of approximately counting(More)
We present a tool called GiS for indexing and querying a large database of labeled, undirected graphs. Such graphs can model chemical compounds, represent contact maps constructed from 3D structure of proteins, and so forth. GiS supports exact subgraph matching and approximate graph matching queries. It adopts a suite of new techniques and algorithms for(More)