Straws in the Wind Blog Articles
My latest article was published on Directions Magazine yesterday.
The article is Scalable Server-side In-database Geoprocessing (thanks to Nora Parker and Adena Schutzberg).
While Tim Osborn gave the presentation (and generated the statistics and charts) all the design and implementation of the performance improvements was done by myself.
All ideas have their genesis. It was something Arthur J Lembo Jnr Ph.D. (thanks Art) said to me in an email that got me thinking about MBR processing. I trialled it inside Manifold GIS and it worked. When this particular problem appeared the experience gained with MBR processing inside Manifold GIS and other ideas in relation to business modelling came together for this solution.
There are still areas that can be improved upon (mainly in the area of automated set up of the tesselation) but I was not paid for this work so it will have to wait until I get the time to play around with the ideas I have for streamlining the approach.
I would also like to have a go at this inside PostGIS. I conducted some tests on some queries (unrelated to this article) in Oracle and PostGIS over the last few days and all I can say is that PostGIS is fast: very, very fast! It might be that the geoprocessing engine inside PostGIS is better than Oracle’s (ie the geometric processing not the indexing and searching) and might lead to a slightly different approach, but I believe the simple ideas behind this article of “rethinking the definition” and “tesselating the space (see my links to Peano etc)” are useful no matter what the software framework.