On Tue, May 20, 2008 at 12:00 PM, Traian Stanev <[EMAIL PROTECTED]> wrote: > > Hi Kenneth, > > The renderer will unfortunately not respect this -- it always passes an empty > property list to FDO, which means select all columns. > > Selecting the right columns from the renderer is difficult in general, since > one would have to go over all the styles and parse any style expressions to > look for property names.
Could the parser for the style and filter definitions be hijacked? they are already processing these values.. > > Selecting all columns does not have much of an overhead for some providers. > Which provider are you using (it was not clear to me from the ticket > description)? This is a real problem when accessing oracle tables which have been setup with Autodesk Map 3d, as it adds a lot of extra ADMP* columns. it's a real performance killer as there can be quite a few columns > > Interestingly, for the SQLite provider, I had the problem of selecting many > columns slowing it down a lot and what I did was in case of empty select > list, return just the ID and geometry columns. If the client then attempts to > read other columns, I reissue the select with additional columns (not this is > done once for the feature reader, not per feature). This way I did not have > to worry about the client selecting the right columns, and got a reasonable > speedup in most cases (of course it is no help if you are actually reading > all properties). > > > Traian > > >> -----Original Message----- >> From: [EMAIL PROTECTED] [mailto:mapguide-users- >> [EMAIL PROTECTED] On Behalf Of Kenneth Skovhede, GEOGRAF A/S >> Sent: Monday, May 19, 2008 8:20 AM >> To: MapGuide Users Mail List >> Subject: [mapguide-users] Speeding up map rendering >> >> I have entered an optimization request some time ago: >> https://trac.osgeo.org/mapguide/ticket/272 >> >> The problem is that the renderer selects all columns from the >> datasource, even though only a few (if any) are used. >> While the general solution might be a bit hard to construct, I have >> another idea. >> >> If I manually add a configuration document/schema with only the desired >> columns, will the renderer respect this? >> Does configuration documents (like the one for ODBC) work for all >> providers? >> >> -- >> Regards, Kenneth Skovhede, GEOGRAF A/S >> >> >> _______________________________________________ >> mapguide-users mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/mapguide-users > _______________________________________________ > mapguide-users mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/mapguide-users > -- Zac Spitzer - http://zacster.blogspot.com (My Blog) +61 405 847 168 _______________________________________________ mapguide-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapguide-users
