OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT Tomáš Richta, Jiří Žára Computer Graphics Group Department of Computer Science and Engineering Czech Technical University in Prague Karlovo nam. 13 Prague (Czech Republic) E – mail:

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 2/17 Outline ► Motivation ► Introduction ► Previous Work ► Conclusion and future work ► Discussion

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 3/17 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

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 4/17 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

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 5/17 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

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 6/17 Previous Work ► GIS/CAD integration ► 3D GIS data model ► An object-oriented approach ► 3D GIS data management

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 7/17 GIS/CAD integration ► GIS aspects  landscape-level analysis and mapping  advanced information tools  mostly 2D modelling  database based  optimized for data retrieval  1:5000 scale and below  constrained editing environment ► CAD aspects  object-level design and drafting  advanced drawing tools  3D modelling  file based  optimized for data design  1: scale  unconstrained editing environment geo-data storevs modelling tool

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 8/17 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

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 9/17 UDM, SSS – Coors, Zlatanova

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 10/17 GeoToolKit - Balovnev et al.

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 11/17 City data model

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 12/17 Building data model

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 13/17 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

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 14/17 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

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 15/17 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

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 16/17 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

Richta T., Žára J. OBJECT-ORIENTED APPROACH TO GIS DATA MANAGEMENT 17/17 Discussion ► Your questions ► Your opinions ► Your recommendations Thanks for Your patience Tomáš Richta, Jiří Žára Computer Graphics Group Department of Computer Science and Engineering Czech Technical University in Prague Karlovo nam. 13 Prague (Czech Republic) E – mail: