Research Issues in Spatio-temporal Database SystemsIntroductionIntroduction (cont’d)Slide 4Slide 5Issues…Issues…Slide 8Slide 9Slide 10Slide 11Slide 12Proposed Indexing for Moving ObjectFunction for Indexing Moving ObjectsStorage, Indexing and QueryingSlide 16ConclusionFall 2000 CS 599 – Spatial and Temporal DatabasesResearch Issues in Spatio-temporal Database SystemsTimos SellisPresented byHandy PatriawanFall 2000 CS 599 – Spatial and Temporal DatabasesIntroductionCommon techniques and toolsR-Tree for both Spatial and TemporalJoin Spatial and Temporal into oneProposed name: STDBMSsSpatio-temporal DBMSsCurrent applicationGeographic Information Systems (GIS)Environmental Information SystemMultimediaFall 2000 CS 599 – Spatial and Temporal DatabasesIntroduction (cont’d)Examples:Fall 2000 CS 599 – Spatial and Temporal DatabasesIntroduction (cont’d)CHOROCHRONOShttp://www.chorochronos.comIssues to be addressed:Ontology, structure and representation of space and timeData model and query languageGUIQuery processing, storage and indexing techniquesArchitectureFall 2000 CS 599 – Spatial and Temporal DatabasesIntroduction (cont’d)Extension of Spatial or Temporal DBMSs is not enoughAdding Temporal support to SDBMSsAdding Spatial support to TDBMSsFinal frontier: unified Spatio-temporal DBMSSpatio-temporal data structures, operators and user-interfacesFall 2000 CS 599 – Spatial and Temporal DatabasesIssues… Ontological IssuesOntology: the study or concern about what kinds of things exist – what entity there are in the universe (http://www.whatis.com)Including Structure and RepresentationFinding a common framework•E.g. common structure and representationFall 2000 CS 599 – Spatial and Temporal DatabasesIssues…Ontological Issues (cont’d)•Ontology of spatial entities: life and motionFall 2000 CS 599 – Spatial and Temporal DatabasesRegionIssues…Ontological Issues (cont’d)•Spatial objects are located “somewhere” in spaceObjectPart LocationFall 2000 CS 599 – Spatial and Temporal DatabasesIssues…Models and Languages for STDBMSsFocus on 3 topics:•Language for spatio-temporal relations•Models and languages for STDBMSs•Design and techniques for STDBMSsResearch is divided into 2 categories:•Tight integration of spatial & temporal•Adding spatial support to temporalFall 2000 CS 599 – Spatial and Temporal DatabasesIssues…Different classes of applicationsEvents in space & time, Moving region, etc.See [4] for more detailsDifferent data structures & operations has been defined as well (see [4])E.g. mpoint x mpoint -> mreal:distanceFall 2000 CS 599 – Spatial and Temporal DatabasesIssues…Constraint database modelsDevelopment in spatio-temporal constraint-based database modelExample: DEDALE•Prototype of a constraint DBMS for spatio-temporal information•See http://www-rocq.inria.fr/verso/dedale/•See http://sikkim.cnam.fr/dedale.html•Still based on SQL•Display the parts of roads which is inside the rectangle RECT drawn on the screen•Select SELECT(r.geometry, RECT)From r in RoadsWhere Satisfy(SELECT(r.geometry, RECT))Fall 2000 CS 599 – Spatial and Temporal DatabasesIssues…Extending current SQLSTSQLAllowing relations to have attributes that are spatial or temporalNot intended for movement of continuously moving or changing objectst=nt=n+1t=n+2XYFall 2000 CS 599 – Spatial and Temporal DatabasesProposed Indexing for Moving Object“Indexing the Positions of Continuously Moving Objects”Simonas Saltenis, Christian S. Jensen, Scott T. Leutenegger and Mario A. LopezIssues: How can we index a moving object (and or changing object) during time periods?Proposed solution:•R*-Tree with time as parameter (boring….)•Function…Fall 2000 CS 599 – Spatial and Temporal DatabasesFunction for Indexing Moving Objectst=nXYTime Functionn Y=XY=Xt=n+1n+1Y=X-2Y=X-2t=n+2n+2 Y=3Y=3Fall 2000 CS 599 – Spatial and Temporal DatabasesStorage, Indexing and QueryingStorage and Indexing:Support for motionBenchmarkingIndexing: R-Tree, Quadtree, etc.Benchmark:Make sure to include everything neededTest access method, data generation, query processing and result analysis---> Common platform for benchmarking the STDBMS as a wholeFall 2000 CS 599 – Spatial and Temporal DatabasesStorage, Indexing and QueryingQuery processing and optimization:Efficient access for spatial, temporal and spatio-temporalSimple cost model for query optimizationStudy of spatial and temporal constraint databaseFall 2000 CS 599 – Spatial and Temporal DatabasesConclusionGood progress… still more work is needed:Devising clean and complete semantics for data models and operatorsEfficient implementationIndexing and query optimizationAlternatives architectures for building
View Full Document
Unlocking...