Olivier Doucet ha scritto: > Hi all, > > I am currently working on a GIS monitoring application that has to > provide 2D view(s) of a dynamic geographic dataset (here a communication > network with its nodes and links, but also moving vehicles). I belive > GeoTools has a lot to offer here. > The network is not supposed to move, but the nodes' attributes will > change over the time and we want to render it accordingly, using SLD rules. > > The point here is that most of our data is vector data (except a > background satellite image) and the complete dataset is not very big, > say maximum 500,000 features in total, but each feature can potentially > be updated (at least one attribute per feature, maybe more), say every 5s. > In addition, there will be a few static features, most likely coming > from shapefiles. > > Since GIS dataset are usually way bigger and more static, I wonder if > the streaming renderer is suited for this dynamic usage. If not what > would you suggest? > Again, if not, how difficult would it be to adapt one of the existing > renderers to ensure a good performance with higher refresh rates and > many changes? > > We are actually considering using a memory datastore. Then my second > question is: is the MemoryDatastore a good option? Or should we > implement our own memory datastore? Extending the existing MemoryDatastore?
I would suggest the following: * use a separate renderer/buffered image for each dynamic layer, and one for the group of static ones, and then merge the images manually. Keep the rendered images around. * if you have enough memory, yes, use a memory data store... with 500.000 features you may want to add a spatial index in it so that bbox queries performed when moving/zooming are fast enough. You'll need a quadtree index, because data will be changing. * when data changes, re-render only the layer that changed, and perform again the image merging. If the application is a server side one, you may want to setup a cache of tiles for the static images too. That should be enough to make it work fast. Cheers Andrea Aime ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Geotools-gt2-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
