Fall 2000CS 599 – Spatial and Temporal Databases Research Issues in Spatio- temporal Database Systems Timos Sellis Presented by Handy Patriawan

Fall 2000CS 599 – Spatial and Temporal Databases 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

Fall 2000CS 599 – Spatial and Temporal Databases Introduction (cont’d) Examples:

Fall 2000CS 599 – Spatial and Temporal Databases Introduction (cont’d) CHOROCHRONOS 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

Fall 2000CS 599 – Spatial and Temporal Databases Introduction (cont’d) 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

Fall 2000CS 599 – Spatial and Temporal Databases Issues… Ontological Issues Ontology: the study or concern about what kinds of things exist – what entity there are in the universe ( Including Structure and Representation Finding a common framework E.g. common structure and representation

Fall 2000CS 599 – Spatial and Temporal Databases Issues… Ontological Issues (cont’d) Ontology of spatial entities: life and motion

Fall 2000CS 599 – Spatial and Temporal Databases Region Issues… Ontological Issues (cont’d) Spatial objects are located “somewhere” in space Object Part Location

Fall 2000CS 599 – Spatial and Temporal Databases 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

Fall 2000CS 599 – Spatial and Temporal Databases 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 -> mreal:distance

Fall 2000CS 599 – Spatial and Temporal Databases Issues… Constraint database models Development in spatio-temporal constraint-based database model Example: DEDALE Prototype of a constraint DBMS for spatio-temporal information See See 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 Roads Where Satisfy(SELECT(r.geometry, RECT))

Fall 2000CS 599 – Spatial and Temporal Databases 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 t=nt=n+1 t=n+2 X Y

Fall 2000CS 599 – Spatial and Temporal Databases 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…

Fall 2000CS 599 – Spatial and Temporal Databases Function for Indexing Moving Objects t=n X Y TimeFunction nY=X t=n+1 n+1 Y=X-2 t=n+2 n+2Y=3

Fall 2000CS 599 – Spatial and Temporal Databases 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 ---> Common platform for benchmarking the STDBMS as a whole

Fall 2000CS 599 – Spatial and Temporal Databases 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

Fall 2000CS 599 – Spatial and Temporal Databases 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