Thanks for all the help on this one, with a hybrid approach, WMS for window dressing, WFS for interaction, and a little simplify()'ing, my performance has increased dramatically.
Just for posterity, the following are some performance indicators for this situation. I have chosen to use the length of the WKT string that the shapes translate to from a postGIS "asText" call, as a surrogate for number of points (this seems easier than trying to get the number of points from a multiploygon): - My initial data set contained 3 MULTIPLOYGONS, WKT string lengths between 62,000 and 85,000 - Data were processed with the postGIS function, simplify, with a tolerance of 0.0025 decimal degrees (trial and error led me to that, no loss of shape integrity) - Shapes simplified to WKT strings of length between 2,100 to 2,800 - Loading times went from about 2 minutes (with several "script not responding" error messages) down to less than 10 seconds - Client/Server Machine is a workstation, WinXP SP2, 2.8 GHz CPU, 1.5 GB RAM, So, while this situation is not exactly precise, it sets some overall bounds, that is, around 7,000 character shape strings will render out in an acceptable time frame (with map pans excellent, i.e., instantaneous rendering, and map zooms reasonable, i.e. ~3.0 seconds to redraw), whereas, on the given system, WKT strings of 200,000 characters was a non-starter. r.b. -----Original Message----- From: Christopher Schmidt [mailto:[EMAIL PROTECTED] Sent: Friday, September 28, 2007 11:42 PM To: Burgholzer,Robert Cc: [email protected] Subject: Re: [OpenLayers-Users] trouble with WFS and Mapserver - Partially solved On Fri, Sep 28, 2007 at 03:42:57PM -0400, Burgholzer,Robert wrote: > Hmm. It seems that every solution finds a new problem. I managed to discern my trouble - it had to do with URL location. > > > > I am testing my application and WFS server all on my local workstation. The issue, after straightening out the baseLayer and projection trouble, came from the location of my script, where I was using a 172.16. notation to access it, and the location of the WFS server, which I was calling as "localhost". Thus, a proxy, or consistent URL scheme was required. I initally ran into the trouble because my script was freezing my browser, and blowing up memory requirements, so I tried "localhost" as my WFS location, and everything sped up, but of course, nothing appeared, because I would have needed a proxy setting. But, the trouble really stemmed from the fact that my shapes are too complex, I suppose. There are 250 shapes in my layer, and that is choking everything up. They are relatively complicated county boundaries. If I set "maxfeatures: 10" in my request, things go faster, and the shapes are rendered in about 30 seconds. However, I really need to be able to see all of my shapes, and would like response times to be reasonable. The WFS url request loads in less than 10 seconds, so, I would not want much more overhead above that. > > > > Any suggestions? Off the top of my head: * simplify() or * WMS Regards, -- Christopher Schmidt MetaCarta _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
