OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT

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OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT

• Tomáš Richta, Jirí ŽáraComputer Graphics Group
• Department of Computer Science and
  EngineeringCzech Technical University in Prague
• Karlovo nam. 13 Prague (Czech Republic)
• E mail richtt1_at_fel.cvut.cz, zara_at_fel.cvut.cz

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Outline

• Motivation
• Introduction
• Previous Work
• Conclusion and future work
• Discussion

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Motivation

• superior goals
• city geographical information system development
  (3D city GIS)
• detailed capturing and modelling of buildings
• applicability of explicit information
• discovered issues
• CAD and GIS integration
• GIS architecture
• GIS data management

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Introduction

• CAD and GIS integration
• key point common data management
• GIS architecture
• non-transparent and expensive solutions
• insufficient adaptability and extensibility
• GIS data management
• old-style techniques (RDBMS)
• unsatisfactory interoperability

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Introduction 2

• Survey of related papers
• opened and topical problem
• many experimental solutions
• few applicable solutions
• no universal solution
• Predominant view
• GIS architecture change needed
• next generation data management needed
• more object-orientation needed

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Previous Work

• GIS/CAD integration
• 3D GIS data model
• An object-oriented approach
• 3D GIS data management

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GIS/CAD integration

• GIS aspects
• landscape-level analysis and mapping
• advanced information tools
• mostly 2D modelling
• database based
• optimized for data retrieval
• 15000 scale and below
• constrained editing environment

• CAD aspects
• object-level design and drafting
• advanced drawing tools
• 3D modelling
• file based
• optimized for data design
• 140-5000 scale
• unconstrained editing environment

geo-data store vs modelling tool
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3D GIS data model

• Examples of 3D data models
• FDS Molenaar
• TEN - Pilouk
• UDM Coors
• SSS Zlatanova
• OO3D - Shi et al.
• GeoToolKit - Balovnev et al.

quite similar deal with basic geometry
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UDM, SSS Coors, Zlatanova
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GeoToolKit - Balovnev et al.
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City data model
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Building data model
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An object-oriented approach

• structural object orientation - any entity,
  independent of whatever complexity and structure,
  may be represented by exactly one object
• operational object orientation operations on
  complex objects are possible without having to
  decompose the objects into a number of simple
  objects
• behavioural object orientation a system must
  allow its objects to be accessed and modified
  only through a set of operations specific to an
  object type
• four main concepts
• encapsulation, inheritance, object identity,
  polymorphism

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3D GIS data management

• Weaknesses of the RDBMS
• poor representation of Real World entities
• semantic overloading
• poor support for integrity
• homogenous data structure
• limited operations
• difficulty handling recursive queries
• impedance mismatch
• other problems
• Experts agree that it is necessary to move to the
  next generation of DBMS object servers

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3D GIS data management 2

• Strengths of the OODBMS
• enriched modelling capabilities
• extensibility
• removal of impedance mismatch
• more expressive query language
• support for schema evolution
• support for long duration transactions
• applicability to advanced database applications
• improved performance
• OODBMS offer the way to evolve the GIS

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Conclusion and future work

• Development of a new 3D GIS should cover
• Object-oriented approaches
• Object-oriented development
• Object-oriented data modelling
• Object-oriented language
• Object-oriented data store

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Discussion

• Your questions
• Your opinions
• Your recommendations
• Thanks for Your patience

Tomáš Richta, Jirí ŽáraComputer Graphics
Group Department of Computer Science and
EngineeringCzech Technical University in
Prague Karlovo nam. 13 Prague (Czech Republic) E
mail richtt1_at_fel.cvut.cz, zara_at_fel.cvut.cz