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Spatial Database: Accomplishments and Research Needs by Fei Shen et al.

This paper outlines the history of spatial databases, highlighting related work by various authors and their contributions. It delves into the accomplishments in spatial data models, querying techniques, file organization, and research needs for the future development of spatial databases.

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Spatial Database: Accomplishments and Research Needs by Fei Shen et al.

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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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