{"id":{"repo_id":"birmingham","oai_identifier":"oai:etheses.bham.ac.uk:213"},"canonical_url":"https://search.dev.ndltd.org/etd/birmingham/oai:etheses.bham.ac.uk:213","repository":{"repo_id":"birmingham","name":"University of Birmingham","base_url":"https://etheses.bham.ac.uk/cgi/oai2"},"display":{"title":"Virtual forced splitting in multidimensional access methods","abstract":"External, tree-based, multidimensional access methods typically attempt to provide B+ tree like behaviour and performance in the organisation of large collections of multidimensional data. The B+ tree’s efficiency comes directly from the fact that it organises data occupying a single dimension, which can be linearly ordered, and partitioned at arbitrary points in that order. Using a multiway tree to partition a multidimensional space becomes increasingly difficult with increasing dimensionality, often leading to the loss of desirable properties like high fanout and low internode overlap. The K-D-B tree is an example of a structure in which one property, that of zero internode overlap, is provided at the expense of another, high fanout. Its approach to doing this, by forced splitting, is shared by a collection of other structures, and in 1995 Freeston suggested a novel approach to mitigate the effects of forced splits, by executing them virtually. This approach has not been taken up widely, but we believe it shows a great deal of promise. In the thesis, we examine the virtual forced splitting approach in depth. We identify a number of problems presented by the approach, and propose solutions to them, allowing us to characterise a general class of virtual forced splitting structures that we call VFS-trees. The efficacy of our approach is demonstrated by our implementation of a new VFS structure, and by what we believe to be the first implementation of a BV-tree, together with new algorithms for region and K Nearest Neighbour search. We further report experimental results on construction, exact-match search and K-NN search of BV-trees, and show how they compare, very favourably, with the corresponding operations on the currently most popular multidimensional file access method, the R*-tree.","abstract_html":"External, tree-based, multidimensional access methods typically attempt to provide B+ tree like behaviour and performance in the organisation of large collections of multidimensional data. The B+ tree’s efficiency comes directly from the fact that it organises data occupying a single dimension, which can be linearly ordered, and partitioned at arbitrary points in that order. Using a multiway tree to partition a multidimensional space becomes increasingly difficult with increasing dimensionality, often leading to the loss of desirable properties like high fanout and low internode overlap. The K-D-B tree is an example of a structure in which one property, that of zero internode overlap, is provided at the expense of another, high fanout. Its approach to doing this, by forced splitting, is shared by a collection of other structures, and in 1995 Freeston suggested a novel approach to mitigate the effects of forced splits, by executing them virtually. This approach has not been taken up widely, but we believe it shows a great deal of promise. In the thesis, we examine the virtual forced splitting approach in depth. We identify a number of problems presented by the approach, and propose solutions to them, allowing us to characterise a general class of virtual forced splitting structures that we call VFS-trees. The efficacy of our approach is demonstrated by our implementation of a new VFS structure, and by what we believe to be the first implementation of a BV-tree, together with new algorithms for region and K Nearest Neighbour search. We further report experimental results on construction, exact-match search and K-NN search of BV-trees, and show how they compare, very favourably, with the corresponding operations on the currently most popular multidimensional file access method, the R*-tree.","abstract_has_math":false,"creators":["Swinbank, Richard"],"institution":"University of Birmingham","degree_name":"d_ph","degree_level":"d_ph","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2008,"date_issued":"2008-12","date_published":"2008-12","updated_at":"2026-07-24T01:10:46Z","subjects":["QA75 Electronic computers. Computer science"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.sponsor","label":"Sponsor","values":["na"]},{"key":"dc:creator","label":"Author","values":["Swinbank, Richard"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2008-12"]},{"key":"dc:date.issued","label":"Date","values":["2008-12"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["College of Engineering & Physical Sciences","School of Computer Science"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Birmingham"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["http://etheses.bham.ac.uk//id/eprint/213/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["d_ph"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["d_ph"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["QA75 Electronic computers. Computer science"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://etheses.bham.ac.uk//id/eprint/213/1/Swinbank08PhD.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["External, tree-based, multidimensional access methods typically attempt to provide B+ tree like behaviour and performance in the organisation of large collections of multidimensional data. The B+ tree’s efficiency comes directly from the fact that it organises data occupying a single dimension, which can be linearly ordered, and partitioned at arbitrary points in that order. Using a multiway tree to partition a multidimensional space becomes increasingly difficult with increasing dimensionality, often leading to the loss of desirable properties like high fanout and low internode overlap. The K-D-B tree is an example of a structure in which one property, that of zero internode overlap, is provided at the expense of another, high fanout. Its approach to doing this, by forced splitting, is shared by a collection of other structures, and in 1995 Freeston suggested a novel approach to mitigate the effects of forced splits, by executing them virtually. This approach has not been taken up widely, but we believe it shows a great deal of promise. In the thesis, we examine the virtual forced splitting approach in depth. We identify a number of problems presented by the approach, and propose solutions to them, allowing us to characterise a general class of virtual forced splitting structures that we call VFS-trees. The efficacy of our approach is demonstrated by our implementation of a new VFS structure, and by what we believe to be the first implementation of a BV-tree, together with new algorithms for region and K Nearest Neighbour search. We further report experimental results on construction, exact-match search and K-NN search of BV-trees, and show how they compare, very favourably, with the corresponding operations on the currently most popular multidimensional file access method, the R*-tree."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Virtual forced splitting in multidimensional access methods"]}]}],"canonical_facts":{"dc:contributor.sponsor":["na"],"dc:creator":["Swinbank, Richard"],"dc:date":["2008-12"],"dc:date.issued":["2008-12"],"dc:description.abstract":["External, tree-based, multidimensional access methods typically attempt to provide B+ tree like behaviour and performance in the organisation of large collections of multidimensional data. The B+ tree’s efficiency comes directly from the fact that it organises data occupying a single dimension, which can be linearly ordered, and partitioned at arbitrary points in that order. Using a multiway tree to partition a multidimensional space becomes increasingly difficult with increasing dimensionality, often leading to the loss of desirable properties like high fanout and low internode overlap. The K-D-B tree is an example of a structure in which one property, that of zero internode overlap, is provided at the expense of another, high fanout. Its approach to doing this, by forced splitting, is shared by a collection of other structures, and in 1995 Freeston suggested a novel approach to mitigate the effects of forced splits, by executing them virtually. This approach has not been taken up widely, but we believe it shows a great deal of promise. In the thesis, we examine the virtual forced splitting approach in depth. We identify a number of problems presented by the approach, and propose solutions to them, allowing us to characterise a general class of virtual forced splitting structures that we call VFS-trees. The efficacy of our approach is demonstrated by our implementation of a new VFS structure, and by what we believe to be the first implementation of a BV-tree, together with new algorithms for region and K Nearest Neighbour search. We further report experimental results on construction, exact-match search and K-NN search of BV-trees, and show how they compare, very favourably, with the corresponding operations on the currently most popular multidimensional file access method, the R*-tree."],"dc:format":["application/pdf"],"dc:identifier.uri":["http://etheses.bham.ac.uk//id/eprint/213/1/Swinbank08PhD.pdf"],"dc:publisher.department":["College of Engineering & Physical Sciences","School of Computer Science"],"dc:publisher.institution":["University of Birmingham"],"dc:relation.isreferencedby":["http://etheses.bham.ac.uk//id/eprint/213/"],"dc:subject":["QA75 Electronic computers. Computer science"],"dc:title":["Virtual forced splitting in multidimensional access methods"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["d_ph"],"dc:type.qualificationname":["d_ph"]},"updated_at":"2026-07-24T01:10:46Z"}