1 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 Outline Introduction & definition Spatial Database Related Work and Authors’ Contribution Scope and Outline Accomplishments Research Needs Summary and Discussion

3 Shen FEii CSCI599-Fall2000 Introduction

4 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 Authors’ Contribution  Identify Recent Accomplishment  Current Research needs

8 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 Three Layer Architecture

10 Shen FEii CSCI599-Fall2000 Accomplishments

11 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 Space Taxonomy… Euclidian Coordinatized Space  Basic Concepts: coordinate system  GIS Operation: North of, South of Metric Space  Formalize the distance relationships

13 Shen FEii CSCI599-Fall2000 Rpresentative Function Specified by OGIS …

14 Shen FEii CSCI599-Fall2000 A Sample of Spatial Operations

15 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 Spatial Data Type Hierarchy by OGIS

17 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 Spatial Querying … Efficient Algorithm  Filter and refine algorithm 1.Filter: returns a set of candidate object which is a superset of the objects fulfilling a predicate 2.Refine: for each candidate, the exact geometry is checked  Plane sweeping algorithm  Spatial join- nested loop, tree matching space partitioning, join-index

19 Shen FEii CSCI599-Fall2000 Query Example Example  Find all lakes which have an area greater than 5 sq. km. And within 20 km. From campground

20 Shen FEii CSCI599-Fall2000 Figures for Spatial Query

21 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 R-Tree Height balanced extension of B+ tree  Objects are represented by MBR

23 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 Research Needs

25 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 Difficult Spatial Queries From GIS Buffer Find the areas 500ft. From power lines Voronoize Classify households as two which supermarket they are closet to Neighborhood Determine slope based on elevation Network Find the shortest path from warehouse to all delivery stops Allocation Where is the best place to build a restaurant Transformation Triangulate a layer based on elevation Bulk Load Load a spatial data file into the database Raster->vector Convert between raster and vector representation

29 Shen FEii CSCI599-Fall2000 Example of Spatial Query Processing Logical Transformation  May not always applicable in spatial database

30 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 Summary and Discussion

33 Shen FEii CSCI599-Fall2000 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 Shen FEii CSCI599-Fall2000 More Spatial Application  GIS, CAD, EOS  Multimedia: Text, Audio, and Video  Web Data

35 Shen FEii CSCI599-Fall2000 Recent Research in Spatial Database