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Spatial Database: Accomplishments and Research Needs

Spatial Database: Accomplishments and Research Needs. presented by Fei Shen from S.Shekar,S.Chawla, S.Ravada,A.Fetterer, X.Liu,C.T.Lu EEE Transactions on Knowledge and Data Engineering 11(1): 45-55, 1999. Outline. Introduction & definition Spatial Database

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Spatial Database: Accomplishments and Research Needs

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  1. Spatial Database: Accomplishments and Research Needs presented by Fei Shen from S.Shekar,S.Chawla, S.Ravada,A.Fetterer, X.Liu,C.T.Lu EEE Transactions on Knowledge and Data Engineering 11(1): 45-55, 1999

  2. Outline • Introduction & definition • Spatial Database • Related Work and Authors’ Contribution • Scope and Outline • Accomplishments • Research Needs • Summary and Discussion

  3. Introduction

  4. Introduction: Spatial Database • DEF: Efficient and Effective management of data related to a space • Physical World, e.g. geography, urban planning, astronomy • Engineering Design, e.g. VLSI circuits design, design of automobile • Conceptual Information Space, e.g. multi-dimension support system, fluid flow, electro-magnetic field • Existing Application • Geographic Information System • Computer Aid Design

  5. Spatial Database (cont’d) • Existing Application • Multimedia Information System • Data Warehousing • NASA Earth Observation System • Commercial Examples • Informix’s Spatial Data Blade • Oracle’s Universal Server with Spatial Data • ESRI’s Spatial Data Engine

  6. Related Work • Won Kim SSD 93 • Research Direction • Validation of relative performance • Query Optimization for spatial queries • Cost Model • Extensible Data Structure and Spatial Operations • Object Oriented Paradigm • Guting VLDB 1994 • Survey and Classification • Spatial Data System • Spatial Data Model • Spatial Query Language • Spatial Indexing • Spatial Join Methods

  7. Authors’ Contribution • Authors’ Contribution • Identify Recent Accomplishment • Current Research needs

  8. Scope and Outline • Object-relational Databases • Spatial Data Types • Spatial Operations • Multi-Dimensional Indexing • Three Layer Architecture • Object Relational Database Management system • Spatial Database • Spatial Application • GIS, MIIS

  9. Three Layer Architecture

  10. Accomplishments

  11. Accomplishments: Space Taxonomy • Set Base Space • Formalize the set relationship • Relational and Object-relational DB uses this model of space • Topological Space • Basic Concept: Neighbor • GIS Operation: overlap, adjacent • Network Space • Basic Concepts: graphs, nodes, edge, connectivity • GIS Operation: connected, path

  12. Space Taxonomy… • Euclidian Coordinatized Space • Basic Concepts: coordinate system • GIS Operation: North of, South of • Metric Space • Formalize the distance relationships

  13. Rpresentative Function Specified by OGIS …

  14. A Sample of Spatial Operations

  15. Accomplishments: Spatial Data Model • Data Abstraction: hides the details of data storage • Field-based Model • Transform a space partition to an attribute domain • Local, focal, zonal operations • Object-based Model • Information Space populated by discrete, identifiable, spatially referenced entity • Distance and Boundary operations

  16. Spatial Data Type Hierarchy by OGIS

  17. Accomplishments:Spatial Querying • Efficient Representation • Object Model • Spaghetti Model • Node-arc-area Model(NAA) model • Double-connected-edge-list (DCEL) • Boundary Representation, Field Based Model • Tessellation • Triangular irregular networks (TIN)

  18. Spatial Querying … • Efficient Algorithm • Filter and refine algorithm • Filter: returns a set of candidate object which is a superset of the objects fulfilling a predicate • Refine: for each candidate, the exact geometry is checked • Plane sweeping algorithm • Spatial join- nested loop, tree matching space partitioning, join-index

  19. Query Example • Example • Find all lakes which have an area greater than 5 sq. km. And within 20 km. From campground

  20. Figures for Spatial Query

  21. Accomplishments: Spatial File Organization and Indices • Space Filling Curve • Clustering • Metric Clustering Technique • Topological Clustering Technique-CCAM • Spatial Indices for point objects • Grid Files, Point-Quad-Tree, KD-tree • Spatial Indices for extended object • R-tree, Field tree, Cell tree • BSP tree, Balanced and Nested Grid Files

  22. R-Tree • Height balanced extension of B+ tree • Objects are represented by MBR

  23. Other Accomplishments • File design for storage on tertiary storage device • Juke boxes • Declustering Method • Dynamic-load balancing techniques • Multi-dimensional spatial data • Hierarchical algorithm • Shortest path computation • View materialization

  24. Research Needs

  25. Research Needs: Space Taxonomy • A sequence of operations on discretized data • Lead to growing errors • Formalize the discetization process • Formalize the associated errors • Formalized the interpolation • E.g. estimate the characteristics of terrain or ecological conditions from a limited number of field measurements.

  26. Research Needs: Spatial Data Model • Network Space • Data Model • Data Types • Node , edge, path • Kernel set of operations • Get successor, shortest path • Field data model toward field based query language

  27. Research Needs: Spatial Query Processing • Query Cost Modeling • Selectivity of Spatial Search • Selectivity of Join Operation • Strategy for bulk loading • Query related to fields and networks

  28. Difficult Spatial Queries From GIS

  29. Example of Spatial Query Processing • Logical Transformation • May not always applicable in spatial database

  30. Research Needs: Spatial File Oragnization and Indices: Physical Leverl • Network Space • File Clustering • Indices • Characterized Access Pattern • Design Access Methods • Concurrency Control • R-link tree for R-tree • Other Spatial Indicies • Data Volume • NASA’s EOS

  31. Research Needs: Other • Benchmark • Earth Science: Sequoia 2000 • GIS • DWH • Transportation • Work Flow Modeling • Concurrency Control • Recovery and Backup • Visual Presentation • Graphic Images • 3D displays • Animation

  32. Summary and Discussion

  33. Summary and Discussion • Research needs with few publications • Spatial graphs • Filed based modeling • Cost modeling • Concurrency control for query processing • Discretization for error propagation • Large number of publication • Object-based data modeling • Spatial data types • Filter and Refine techniques for query processing • Spatial Indexing

  34. More • Spatial Application • GIS, CAD, EOS • Multimedia: Text, Audio, and Video • Web Data

  35. Recent Research in Spatial Database

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