XML data integration tools are facing a variety of challenges for their efficient and effective operation. Among these is the requirement to handle a variety of inconsistencies or mistakes present in the data sets. In this paper we study the problem of integrating XML data sources through index assisted join operations, using notions of approximate match in the structure and content of XML docu...

Many emerging applications benefit from the extraction of geospatial data specified at different resolutions for viewing purposes. Data must also be topologically accurate and up-to-date as it often represents real-world changing phenomena. Current multiresolution schemes use complex opaque data types, which limit the capacity for in-database object manipulation. By using z-values and B+trees t...

The domain of spatiotemporal applications is a treasure trove of new types of data and queries. However, work in this area is guided by related research from the spatial and temporal domains, so far, with little attention towards the true nature of spatiotemporal phenomena. In this work, the focus is on a spatiotemporal sub-domain, namely the trajectories of moving point objects. We present new...

A lot of recent work has studied strategies related to bulk loading of large data sets into multidimensional index structures In this paper we address the problem of bulk insertions into existing index struc tures with particular focus on R trees which are an important class of index structures used widely in commercial database systems We pro pose a new technique which as opposed to the curren...

Finding the most accessible locations has a number of applications. For example, a user may want to find an accommodation that is close to different amenities such as schools, supermarkets, and hospitals etc. In this paper, we study the problem of finding the most accessible locations among a set of possible sites. The task is converted to a top-k query that returns k points from a set of sites...

Constraint search trees are a generic approach to search trees where all operations are defined in terms of constraints. This abstract viewpoint makes clear the fundamental operations of search trees and immediately points to new possibilities for search trees. In this paper we present height-balanced constraint search trees (HCSTs), a general approach to building height-balanced index structur...

Spatial databases have been increasingly and widely used in recent years. The R-tree proposed by Guttman is probably the most popular dynamic index structure for eciently retrieving objects from a spatial database according to their spatial locations. However, experiments show that only about 70% storage utilization can be achieved in Guttman's R-tree and its variants. In this paper, we propos...

Given a group G, RF-theory constructs a new group RF(G) and an action RF(G) → Isom(XG) by isometries of RF(G) on a canonically associated R-tree XG. We give an overview mostly focusing on the more basic aspects of this theory, up to and including the universal property of RF-groups and their associated R-trees.

Recently there has been an increasing interest in supporting bulk operations on multidimensional index structures. Bulk loading refers to the process of creating an initial index structure for a presumably very large data set. In this paper, we present a generic algorithm for bulk loading which is applicable to a broad class of index structures. Our approach differs completely from previous one...