Filtering algorithms for information retrieval models with named attributes and proximity operators

Abstract

In the selective dissemination of information (or publish/ subscribe) paradigm, clients subscribe to a server with continuous queries (or profiles) that express their information needs. Clients can also publish documents to servers. Whenever a document is published, the continuous queries satisfying this document are found and notifications are sent to appropriate clients. This paper deals with the filtering problem that needs to be solved efficiently by each server: Given a database of continuous queries db and a document d, find all queries q ∈ db that match d. We present data structures and indexing algorithms that enable us to solve the filtering problem efficiently for large databases of queries expressed in the model AWP which is based on named attributes with values of type text, and word proximity operators.

Self-organising Applications Using Lightweight Agents

“…However, more experience with such applications is necessary in order to come up with a methodology for the development of software systems using lightweight agents (presumably, this methodology will be based on traditional software engineering principles and new inspirations from selforganization). The use of self-organization and the sophisticated indexing schemes of [40] helped us to achieve high performance and scalability in P2P-DIET. We have not carried out yet detailed experimentations of P2P-DIET beyond these reported in [40], so it is not clear at this stage how much of the scalability of P2P-DIET is due to indexing and how much to the self-organizing protocols utilized.…”

“…The use of self-organization and the sophisticated indexing schemes of [40] helped us to achieve high performance and scalability in P2P-DIET. We have not carried out yet detailed experimentations of P2P-DIET beyond these reported in [40], so it is not clear at this stage how much of the scalability of P2P-DIET is due to indexing and how much to the self-organizing protocols utilized.…”

On the use of negation in Boolean IR queries

“…Even more extended features, mixing Boolean operators with proximity constraints between certain keywords can be found in the word pattern models for Boolean Information Retrieval WP and AWP (Tryfonopoulos et al 2004). Note that similarly to database queries, the metrical constraints allow a precise description of the required expressions.…”

LibraRing: An Architecture for Distributed Digital Libraries Based on DHTs

“…We will often say that this node is responsible for key k. For example in the network shown in Figure 1(b), a key with identifier 30 would be stored at node N 32. In fact node N 32 would be responsible for all keys with identifiers in the interval (21,32].…”

“…, s k . S utilises these data structures at filtering time to find quickly all continuous queries cq that match an incoming publication p. This is done using an algorithm that combines algorithms BestFitTrie [21] and SQI [23].…”