Thank you for the response David. I have optimized the query all I can. I have optimized the query to the point that even with all categories selected, the query has a run time of 52 ms. I can only assume that the issue lies with the generation of the images. I will try to run it without the "IN" part of the query, but I can't imagine that it'st he problem. I think the problem is that there are a large number of symbols that need to be generated, and it's taking mapserver a long time to load them in. Also, yes I have indexes on all columns that I am calling in, and yes, they are all using the same SRS. I am still trying a few more things, but I don't think it's the database query that's causing the problem.
On Fri, Apr 30, 2010 at 9:37 AM, Fawcett, David (MPCA) < david.fawc...@state.mn.us> wrote: > Adam, > > > > It sounds like you have boiled the issue down to too much of a time lag > between the time the query is executed and the image appears in the client. > > > > > Is it taking a long time for MapServer to draw the image, or is it the > delivery of the image to the requesting machine and subsequent placement in > the client? > > > > If it is taking MapServer a long time, maybe there are some more data > optimizations that you can do. Is there a better way to structure your > data, can you do any pre-processing? Is it all in the same SRS, got > attribute and spatial indexes? I have used the SQL IN for some apps with > reasonable performance, but in the last 6 months or so, there were some > posts on this list comparing the use of IN to a layer (or class?) filter. > The latter solution was significantly faster. > > > > If it is taking a long time to get to the client, then that is likely an > infrastructure issue on either end. > > > > If you want some more help digging in more deeply, post some more stats and > mapfile snippets. > > > > David. > > > > *From:* mapserver-users-boun...@lists.osgeo.org [mailto: > mapserver-users-boun...@lists.osgeo.org] *On Behalf Of *Adam Eskreis > *Sent:* Thursday, April 29, 2010 4:24 PM > *To:* Lime, Steve D (DNR) > *Cc:* mapserver-users@lists.osgeo.org > > *Subject:* Re: [mapserver-users] Re: WMS and tiles cutting off > > > > I tried doing ratio:1 unfortunately it doesn't seem like enough of a > performance increase. Separate layers for each category is an option, > however, there are over a hundred categories, and any combination of > categories can be on at any given time, so this could prove to have > performance issues of it's own. However, I thank you guys Steve and Kaipi > for your advice. I think I am just going to go back to my old method, which > was using php mapscript to generate the tiles, then each time the user > selected new categories, purge the cache and remake the mapfile. It's not > the ideal solution but it seems to be the only one. > > Thanks again, > > -Adam > > On Thu, Apr 29, 2010 at 3:50 PM, Lime, Steve D (DNR) < > steve.l...@state.mn.us> wrote: > > Note that by default I believe openlayers will request an image that is > *much* larger than what is visible. Setting the layers (OL) ratio:1 makes it > the same size as the view port and that can speed up rendering considerably. > > Alternatively you could create a separate set of tiles for each category I > suppose and switch OL layers as necessary... > > > Steve > > ________________________________________ > From: mapserver-users-boun...@lists.osgeo.org [ > mapserver-users-boun...@lists.osgeo.org] On Behalf Of Adam Eskreis [ > aeskr...@gmail.com] > > Sent: Thursday, April 29, 2010 2:25 PM > > To: mapserver-users@lists.osgeo.org > Subject: Re: [mapserver-users] Re: WMS and tiles cutting off > > Ok, I just gave an untiled layer a try, unfortunately though, due to the > large amount of symbols being displayed on the screen, there is about a 2 > second delay every time the map is panned. My client will most certainly > find this unacceptable. I have tried using smaller images, but I cannot > sacrifice any more quality. I believe my database query to be as optimized > as it can be (has about 50 ms runtime, I honestly don't think I can get it > any lower than that). > > If these are the only options, is there something else besides WMS that you > all would recommend using to solve this issue? > > Thanks, > -Adam > > On Thu, Apr 29, 2010 at 2:54 PM, Lime, Steve D (DNR) < > steve.l...@state.mn.us<mailto:steve.l...@state.mn.us>> wrote: > So use two layers. One for the background, use tilecache for that. Then use > an untiled wms/mapserver layer for the overlayed points. - Steve > ________________________________________ > > From: mapserver-users-boun...@lists.osgeo.org<mailto: > mapserver-users-boun...@lists.osgeo.org> [ > mapserver-users-boun...@lists.osgeo.org<mailto: > mapserver-users-boun...@lists.osgeo.org>] On Behalf Of Adam Eskreis [ > aeskr...@gmail.com<mailto:aeskr...@gmail.com>] > > Sent: Thursday, April 29, 2010 1:24 PM > > To: mapserver-users@lists.osgeo.org<mailto:mapserver-users@lists.osgeo.org > > > > Subject: Re: [mapserver-users] Re: WMS and tiles cutting off > > I have thought about using tilecache with metatiling, however there is a > caveat about this map that i forgot to mention in my main post, and it has > to do with that "categories" parameter. Basically, each point/symbol on the > map has an associated category in the database backend. I am using > mapserver/WMS parameters to change the categories which are called. Each > time the user selects a category, only the points in that category are > shown. My query in the mapfile looks something like thi: > > SELECT point_geom,gid,symbol,angle FROM mapdata WHERE category > IN(%CATEGORIES%)"; > > And each time the user changes the categories, I use openlayers to merge > new parameters, and input the new category values that should be used. Is > tilecache still useable if I have a system like this set up? > > Thanks, > -Adam > > On Thu, Apr 29, 2010 at 6:14 AM, kaipi <mapcoll...@gmx.net<mailto: > mapcoll...@gmx.net><mailto:mapcoll...@gmx.net<mailto:mapcoll...@gmx.net>>> > wrote: > > Hi, > > you can use http://tilecache.org/ Tilecache with the option metatiling > enabled. With metatiling enabled Tilecache will fetch larger tiles (eg. > 4096x4096) from Mapserver and will cut them into smaller tiles (eg. > 256x256). It will also increase performance because Mapserver does not need > to render tiles when they are already in cache. > > kaipi > -- > View this message in context: > http://osgeo-org.1803224.n2.nabble.com/WMS-and-tiles-cutting-off-tp4978418p4979280.html > Sent from the Mapserver - User mailing list archive at Nabble.com. > _______________________________________________ > mapserver-users mailing list > > mapserver-users@lists.osgeo.org<mailto:mapserver-users@lists.osgeo.org > ><mailto:mapserver-users@lists.osgeo.org<mailto: > mapserver-users@lists.osgeo.org>> > > http://lists.osgeo.org/mailman/listinfo/mapserver-users > > >
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