Research Issues in Spatio-temporal Database Systems

1
Research Issues in Spatio-temporal Database
Systems

• Timos Sellis
• Presented by
• Handy Patriawan

2
Introduction

• Common techniques and tools
• R-Tree for both Spatial and Temporal
• Join Spatial and Temporal into one
• Proposed name STDBMSs
• Spatio-temporal DBMSs
• Current application
• Geographic Information Systems (GIS)
• Environmental Information System
• Multimedia

3
Introduction (contd)

• Examples

4
Introduction (contd)

• CHOROCHRONOS
• http//www.chorochronos.com
• Issues to be addressed
• Ontology, structure and representation of space
  and time
• Data model and query language
• GUI
• Query processing, storage and indexing techniques
• Architecture

5
Introduction (contd)

• Extension of Spatial or Temporal DBMSs is not
  enough
• Adding Temporal support to SDBMSs
• Adding Spatial support to TDBMSs
• Final frontier unified Spatio-temporal DBMS
• Spatio-temporal data structures, operators and
  user-interfaces

6
Issues

• Ontological Issues
• Ontology the study or concern about what kinds
  of things exist what entity there are in the
  universe (http//www.whatis.com)
• Including Structure and Representation
• Finding a common framework
• E.g. common structure and representation

7
Issues

• Ontological Issues (contd)
• Ontology of spatial entities life and motion

8
Issues

• Ontological Issues (contd)
• Spatial objects are located somewhere in space

9
Issues

• Models and Languages for STDBMSs
• Focus on 3 topics
• Language for spatio-temporal relations
• Models and languages for STDBMSs
• Design and techniques for STDBMSs
• Research is divided into 2 categories
• Tight integration of spatial temporal
• Adding spatial support to temporal

10
Issues

• Different classes of applications
• Events in space time, Moving region, etc.
• See 4 for more details
• Different data structures operations has been
  defined as well (see 4)
• E.g. mpoint x mpoint -gt mrealdistance

11
Issues

• Constraint database models
• Development in spatio-temporal constraint-based
  database model
• Example DEDALE
• Prototype of a constraint DBMS for
  spatio-temporal information
• See http//www-rocq.inria.fr/verso/dedale/
• See http//sikkim.cnam.fr/dedale.html
• Still based on SQL
• Display the parts of roads which is inside the
  rectangle RECT drawn on the screen
• Select SELECT(r.geometry, RECT)From r in
  RoadsWhere Satisfy(SELECT(r.geometry, RECT))

12
Issues

• Extending current SQL
• STSQL
• Allowing relations to have attributes that are
  spatial or temporal
• Not intended for movement of continuously moving
  or changing objects

13
Proposed Indexing for Moving Object

• Indexing the Positions of Continuously Moving
  Objects
• Simonas Saltenis, Christian S. Jensen, Scott T.
  Leutenegger and Mario A. Lopez
• Issues How can we index a moving object (and or
  changing object) during time periods?
• Proposed solution
• R-Tree with time as parameter (boring.)
• Function

14
Function for Indexing Moving Objects
15
Storage, Indexing and Querying

• Storage and Indexing
• Support for motion
• Benchmarking
• Indexing R-Tree, Quadtree, etc.
• Benchmark
• Make sure to include everything needed
• Test access method, data generation, query
  processing and result analysis
• ---gt Common platform for benchmarking the STDBMS
  as a whole

16
Storage, Indexing and Querying

• Query processing and optimization
• Efficient access for spatial, temporal and
  spatio-temporal
• Simple cost model for query optimization
• Study of spatial and temporal constraint database

17
Conclusion

• Good progress still more work is needed
• Devising clean and complete semantics for data
  models and operators
• Efficient implementation
• Indexing and query optimization
• Alternatives architectures for building STDBMSs