Dear GeoServer users, I have trouble figuring out fast and scalable way to serve lightning data via GeoServer.
My dataset consists of several million points spread over central Europe spanning several years. I have approximately 3M lightning strikes right now and it's just a fraction of what I'll have to handle ultimately. I'm using Oracle Locator database with both spatial and normal indexes and while it has a few quirks it works reasonably well when the amount of lightnings is small (i.e. in thousands or tens of thousands). While my WMS client will never allow to show more than 2 hours worth of data (that's small amount of lightning strikes) there are particular WMS requests which take a very long time: when I want to see a "bigger picture" of all lightning strikes in central Europe during a specified short period of time. The core of the problem is my data have both spatial and temporal dimension and there is no spatio-temporal index in Oracle Locator. So even if regular index on the time dimension can limit the number of features to a few thousands in the blink of an eye, the spatial index over the point geometry column won't help much (since the BBOX in the request covers the whole area anyway) and is in fact doing harm. The query found in GeoServer logs runs really fast If I omit the spatial index clause in such case (just a few hundred ms compared to 6-7 seconds for the full query with SDO_FILTER function call). Another bad thing is my colleagues predict that the performance will get worse with more data in the table once it won't fit into RAM and the database engine will have to use hard drives for processing. The performance improves rapidly as I zoom to larger scales (smaller areas), where the spatial index selects just a small subset of data. However, I'd like to be able to serve the whole central Europe quickly, too. One possible solution is to add the time dimension to my spatial index (so it's 3D instead of 2D), but I'm afraid GeoServer won't be able to retrieve data from such index (it won't be EPSG:3857 geometry anymore). Another solution from an Oracle forum suggests using partitioning over time and have separate spatial index for each partition, but that requires expensive Oracle Enterprise license (which was not budgeted in the project of course) and it's just dividing the problem by a constant factor anyway. So, since I'm out of my own ideas, how would you handle this situation? What other tools or formats are useful? Is the Postgres/PostGIS combo better at serving large-scale spatio-temporal datasets (with regard to GeoServer)? Many thanks for any help! -- Peter Kovac IMS Programmer MicroStep-MIS peter.ko...@microstep-mis.com ------------------------------------------------------------------------------ Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape _______________________________________________ Geoserver-users mailing list Geoserver-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geoserver-users
