1. Moving Point Type OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-06 Dagstuhl 1 A ‘movingpoint’ type for a DBMS Wilko Quak - TUDelft

2. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-062Moving Point Type Overview Clarification Design considerations for movingpoint type Implementation in MonetDB

3. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-063Moving Point Type Moore’s Law makes some problem go away 50% p/year: - cpu speed - mem size - mem bandwidth - disk bandwidth 1% p/year: - mem latency 10% p/year: - disk latency #points in laser scan #available GPS logs #cadastral parcels

4. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-064Moving Point Type Examples of moving points data

5. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-065Moving Point Type What do I want with the data? Can I find all occurences of missing data because someone used subway? What is the optimal distance between busstops to get people to the trainstation as fast as possible? Is that man smiling? Flocks and other patterns? More……?

6. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-066Moving Point Type Requirements Should work with all kinds of data Should be extensible (to moving region, or dynamic integer??? (orthogonal?)) Queries should be understandable Should work seamlessly together with point/line/polygon + datetime I want to store my original measurements in a reproducably and compact way

7. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-067Moving Point Type Two possible mappings of movinpoint type to DBMS: create table person( name string, location point dynamic continuous, salary integer dynamic discrete); create table person( name string location movingpoint); This is ortogonal but requires a highly extensible DBMS to implement This is not that bad and is easier to do in existing DBMS

8. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-068Moving Point Type Things that should be efficient Range queries in time Range queries on location Nearest neigbour search (Fréchet distance) Joins

9. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-069Moving Point Type Debatable Issues What to do with accuracy. (Current implementations of point line an polygon don’t have it. Do we miss it?) More interpolation types than: linear or constant. Do we want a multi-scale type?

10. Moving Point Type OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-06 Dagstuhl 10 MonetDB A novel spatial column-store DBMS Martin Kersten - CWI Niels Nes - CWI Wilko Quak - TUDelft Maarten Vermeij - TUDelft

11. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-0611Moving Point Type MonetDB design considerations Multi-model database kernel support Extensible data types, operators, accelerators Database hot-set is memory resident Simple data structures are better Index management should be automatic Do not replicate the operating system Optimize when you know the situation Cooperative transaction management

12. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-0612Moving Point Type MonetDB - Physical data organization Binary Association Tables

13. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-0613Moving Point Type Monet kernels MAPI protocol JDBC C-mapi lib Perl End-user application ODBC PHP Python SQL XQuery MonetDB product family

14. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-0614Moving Point Type MonetDB heap layout

15. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-0615Moving Point Type Redundancy IDXYZT 1121532443415723.141592006-06-02:16.47 2121532743415793.22006-06-02:16.57 31215400434159010.02006-06-02:17.07 41215321434170611.02006-06-02:16.17 This can be compressed away in heap structure

16. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-0616Moving Point Type Implementation options for heap structure 1. Implement as BLOB with x1,y1,z1,t1,x2,y2,z2,t2,… -Similar to polyline implementations. -Index with rtree index on x,y,z,t -Is reasonably efficient for small objects. 2. Build a kinetic structure in the heap -Will be efficient for querying -Compression schema might be tricky

17. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-0617Moving Point Type Conclusions / Discussion DBMS support for multipoints will make querying collections of moving points easier and more efficient. MonetDB looks like a good option for implementation.

18. OTB Research Institute for Housing, Urban and Mobility Studies 2008-11-0618Moving Point Type MonetDB extension mechanism for types