1. Spatio-temporal databases
Advanced Database Systems
Spatio-temporal databases
Nguyễn khắc trung
Văn đình vỹ phương
Trương viết toán
Đào thị thu trang
2015

2. Outline Part 1: Definition Part 2: Spatio - Temporal Data Models
Part 3: Comparing and Conclusion
Part 4: Questions & Answers

3. Part 1: Definition on spatial-temporal data modeling
A spatiotemporal database is a database that manages both space and time information.
Common examples include:
Tracking of moving objects.
A database of wireless communication networks

4. Definition on spatial-temporal data modeling
Spatial-temporal data model are the core of Spatial-Temporal Information System (STIS). They define object data types, relationships, operations and rules to maintain database integrity.
Research both on spatial database and temporal database is basis for spatial-temporal database models.

5. Temporal semantics Granularity Temporal operations Time density
Representation of time
Transaction / Valid time
Time order
Lifespan

6. Spatial semantics Structure of space Orientation/Direction Measurement
Topology

7. The spatial-temporal semantics
Data types
Primitive notions
Type of changes
Evolution in time and space
Space-time topology
Object identities
Dimensionality

8. Query capabilities
Queries about locations, spatial properties and spatial relationships.
Queries about time, temporal properties and temporal relationships.
Queries about spatio-temporal behaviors and relationships.

9. Part 2: Spatio-Temporal Model
Event-Oriented,
Object-Relationship,
Object-Oriented,
Moving object, …

10. The land informations system
Example the change in real.

11. Part 2: Spatio-Temporal Model Event-Oriented
Event Oriented Spatio-Temporal Data Model (ESTDM)
Previous model not identify individual changes or events to data set
raster-based event- oriented
* Event Oriented Spatio- Temporal Data Model (ESTDM)
-Group time-stamped layers
-Store changes in relation (not snapshot as Snapshot model)
A header file contains information its thematic domain, pointer to a base map, and pointers to the first and last event lists.
The base map is initial snapshot of a single theme of interest in a geographic area.
Every event is time- stamped and associated with a list of event components to indicate where changes have occurred

12. Part 2: Spatio-Temporal Model Event-Oriented
Amendment Vector
*another event-oriented approach, called the amendment vector approach
A base state (or a final state) is overlaid with amendment maps,
representing the events in the database
The advantage of this representation is:
information about what happened to the objects is stored in the database.
The time domain considers discrete, relative, linear modeling

13. Part 2: Spatio-Temporal Model Object-Relationship Model (O-R Model)
Previous model:
enhanced current GISs realistic world
However:
None covered the description of change processes
existing models concern design (rather than: representation of natural environmental changes, processes and events)

14. Part 2: Spatio-Temporal Model Object-Relationship Model (O-R Model)
Different methodologies present:
Modul-R
Mecosig and Pollen
Object-Oriented
Modeling Application Data with Spatio- temporal features (MADS). implemented following object relationship
The implementation of object-relationship models describe “processes, which act on the geometric attributes of an entity” and illustrate the importance of capturing the processes, which cause change in connection with space and time.

15. Part 2: Spatio-Temporal Model Object-Relationship Model (O-R Model)
MADS
incorporates space & time model basics to object- relationship model
At the same time, the object properties, which are required to be captured in the spatio-temporaldatabases, are stated.
The processes influencing a single object’s geometry are described as the characteristic of the geometry attribute
The spatio-temporal processes are visualized through icons in the schema.
- spatio-temporal database processes allow users to handle the complex data models required by higher-level abstracted spatio-temporal applications.
 Therefore, the types of processes were classified and represented as relationships between involved spatio-temporal objects.

16. Part 2: Spatio-Temporal Model Object-Relationship Model (O-R Model)

17. Object-Oriented Data Model (O-O Model)
Event oriented: focus on event, capture spatial part in discrete time
Object relation: define each object- and relationship between them.
Object oriented: focus on object, adapt with OO programming
Query: trees x in region Q at time T3

18. Object-Oriented Data Model (O-O Model)
4 advantages of O-O:
A Single Object can represent the whole history of an entity
Queries are simple
Efficient temporal data handling
Uniform treatment of S-T Data handling
1: one obj can content all information of one obj in real
2: relationship between obj
3: time can be store as part of obj
4: time and S is part of obj

19. Object-Oriented Data Model (O-O Model)
Worboys ST-object
ST-OBJECT
BiTemporal
…….
BiTemporal: valid time and transaction time
From Start to End
Spatio

20. Object-Oriented Data Model (O-O Model)
Wachowicz and Healy (version management)
ROOT
ST-O
G.To.Th
complex versioned objects with geometric, topological and thematic properties
A new instance of an object with a different identifier is created for every version
ST-O
G’.To’.Th’
ST-O
G.To.Th’

21. Object-Oriented Data Model (O-O Model)
Bonfatti and Monari (Law)
ST-OBJECT
LAW…….
Strt
characterize object structure: structure and relationships.
laws describe the behaviour of the components
geographical structures and phenomena
laws describe the behaviour of the components
not possible for the LIS(Land Information System)
Applications listed as spatio-temporal dominant (simulation modeling, electronic charting, environmental management, etc.)
Rel

22. Object-Oriented Data Model (O-O Model)
Rojas-Vega and Kemp - SIDL
Structure and Interface Definition Language (SIDL)
geographical structures and phenomena
laws describe the behaviour of the components
not possible for the LIS(Land Information System)
Applications listed as spatio-temporal dominant (simulation modeling, electronic charting, environmental management, etc.)

23. Object-Oriented Data Model (O-O Model)
Object Model Technique - OMT
Its high-level representation abstraction
Representing data varying in 3D space and time
presented for storage of data sets concerning environmental monitoring and simulations

24. Object-Oriented Data Model (O-O Model)
Object Model Technique - OMT
STO – Data set
LAW…….
Data set(t)
The values in a data set can be spread either regularly or irregularly within the 4D space by x, y, z and t

25. Object-Oriented Data Model (O-O Model)
Object Model Technique - OMT
The values in a data set can be spread either regularly or irregularly within the 4D space by x, y, z and t

26. Object-Oriented Data Model (O-O Model)
Object Model Technique - OMT
The values in a data set can be spread either regularly or irregularly within the 4D space by x, y, z and t

27. Moving Object Data Models
when we try an integration of space and time, we are dealing with geometries changing over time
In general, geometries cannot only change in discrete steps, but continuously, and then we are talking about moving objects.

28. Moving Object Data Models
Time dimension
Space vs Time
Position
Extention
when we try an integration of space and time, we are dealing with geometries changing over time
In general, geometries cannot only change in discrete steps, but continuously, and then we are talking about moving objects.
growing or shrinking regions

29. Moving Object Data Models
Time dimension
Linear
Discrete/continuous
Absolute time model
The past presented is data-type oriented
with emphasis on generality, closure and consistency
Captures the change and movement

30. Moving Object Data Models
Discrete representation
“slices”
“simple” function
on pair (I, u)
The past presented is data-type oriented
how “moving” types are represented.
where I is a time interval and u is some representation of a simple function defined within that time interval.

31. Moving Object Data Models
Discrete representation
“slices”
“simple” function
on pair (I, u)
The past presented is data-type oriented
how “moving” types are represented.
where I is a time interval and u is some representation of a simple function defined within that time interval.

32. Moving Object Data Models
SpatioTemporal predicates
dynamic attributes
 motion vector (with threshold)
 speed,acceleration
dynamic attributes, i.e. attributes that change continuously as a
function of time, without being explicitly updated.
DBMS to predict the future location of a moving object by providing a motion vector
motion vector which consists of its location, speed and direction for a recent period of time

33. Part 3: Comparing and Conclusion
Temporal semantic
Spartial semantic
Spartio-temporal semantic
Query capabilities

34. Temporal All support multiple granularities (except Moving object)
Assume time order is linear
Earlier: assume discrete modeling of time. Currently: both levels discrete/continuous
Some new models: handling events’ duration and history of ST object (lifespan)
Moving object: single granularity

35. Spatial Base on spatial data models
Assume vector structure of space (raster is just adopted by 4 models)
Only O-O and Moving Object
Orientation and direction of ST object during change/movement across space and time dimensions
support all type of spatial data handling
Vector representation is much simpler and generic, easily be transformed to Raster

36. In spatio-temporal
Data Model
Data types
Primitive Notions
Types of change
Dimensionality
Event Oriented
Data, event & raster structures
Event, amendment maps
Only Discrete
All
O-R
Point, line, region
Entity, relationship
Not movement
O-O
Simple descriptions, point, line, area
Object, attribute, relationship
All types
Moving Objects
Moving point, region
Sliced representation 2D
Comparison related to model domain
Common data type: point, line, region, temporal point, temporal interval
Approach data type: parametric rectangles and moving points
Most capture different dimensionality representation of ST-O

37. Query capability All models support for attribute and simple queries
Composite query -> describe complex and evolving real work object
Moving object can resolve any type of ST Query
Queries in all 3 categories: temp, spatial, spatial-temporal DB
Time dimension is considered to be continuous
Some models support variety ST Q, but can not cover all possible physical process

38. Conclusions The reviewed models vary on following features:
Formalisation
Implementation
Tool
Application
Spatial model
Temporal model

40. Q&A
on the Paper.

41. Q&A Câu 1: What are talk about of Event-Oriented Model?
A. It is easily identify changes or events in data set.
B. It uses transaction log to backwards the changes
C. It is easily to change the vector-based system
D. It uses amendment vector approach and overlay maps

42. Q&A
Câu 2:
What is NOT an advantage of using object-oriented approach in STDB?
A. Use multiple objects to represent the whole history of an entity.
B. Uniform treatment of spatial and temporal data handling
C. Queries are simple, because they deal with each single object of an entity
D. Efficient temporal data handling

43. Q&A Câu 3: Moving Object Data Models talk about:
A. From an Object to another Object in the time interval
B. Attributes of Object can continuously represent by time functions.
C. From an Object to another Object by its time functions.
D. Temporal part of Object can continuously be recorded.

44. Q&A
Câu 4:
Currently, which data model can resolve any type of spatio-temporal query? A. Event Oriented
B. Object-Relationship
C. Object-Oriented
D. Moving object