Spatial Database: Accomplishments and Research Needs

1Shen FEii

CSCI599-Fall2000CSCI599-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

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CSCI599-Fall2000CSCI599-Fall2000 Outline

Introduction & definition• Spatial Database

• Related Work and Authors’ Contribution

• Scope and Outline

Accomplishments

Research Needs

Summary and Discussion

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Introduction

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CSCI599-Fall2000CSCI599-Fall2000Introduction: 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

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CSCI599-Fall2000CSCI599-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

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CSCI599-Fall2000CSCI599-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

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CSCI599-Fall2000CSCI599-Fall2000 Authors’ Contribution

Authors’ Contribution Identify Recent Accomplishment

Current Research needs

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CSCI599-Fall2000CSCI599-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

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Three Layer Architecture

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Accomplishments

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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

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CSCI599-Fall2000CSCI599-Fall2000 Space Taxonomy…

Euclidian Coordinatized Space Basic Concepts: coordinate system

GIS Operation: North of, South of

Metric Space Formalize the distance relationships

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Rpresentative Function Specified by OGIS …

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CSCI599-Fall2000CSCI599-Fall2000 A Sample of Spatial Operations

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CSCI599-Fall2000CSCI599-Fall2000Accomplishments: 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

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CSCI599-Fall2000CSCI599-Fall2000Spatial Data Type Hierarchy by

OGIS

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CSCI599-Fall2000CSCI599-Fall2000Accomplishments: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)

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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

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CSCI599-Fall2000CSCI599-Fall2000Query Example

Example Find all lakes which have an area greater than 5 sq. km. And

within 20 km. From campground

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CSCI599-Fall2000CSCI599-Fall2000 Figures for Spatial Query

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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

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CSCI599-Fall2000CSCI599-Fall2000 R-Tree

Height balanced extension of B+ tree Objects are represented by MBR

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CSCI599-Fall2000CSCI599-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

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Research Needs

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CSCI599-Fall2000CSCI599-Fall2000Research 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.

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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

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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

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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

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Example of Spatial Query Processing

Logical Transformation May not always applicable in spatial database

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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

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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

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Summary and Discussion

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CSCI599-Fall2000CSCI599-Fall2000Summary 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

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More Spatial Application

GIS, CAD, EOS

Multimedia: Text, Audio, and Video

Web Data

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Recent Research in Spatial Database

Documents

Spatial Database: Accomplishments and Research Needs