[mapserver-users] querying WMS layer / WFS reprise

[Daniel Morissette]

Gregor Mosheh wrote:
> 
> The queries were being done directly to the WFS server (telnet localhost
> 80), too, not via a MapServer WFS client. It wasn't a matter of the data
> taking a while to transfer: there was simply no activity for several
> minutes, and then the data came across. It was definitely something
> "inside" the WFS server, as opposed to the rendering or transit of the
> data.
> 
> The result sets weren't very large: 20 or less multipolygons (zipcode
> areas). A fair chunk of data, but it's over a LAN. The same query via WMS
> responded in 1-2 seconds, indicating that it's the WFS stuff, as opposed
> to the underlying data, that's taking the time.
> 

I think you are using PostGIS as your data layers, is that correct?

MapServer's uses internal queries for GetFeature WFS requests, and a 
performance problem with MapServer queries on large PostGIS layers has 
been discussed on this list and on the chameleon lists in the last few days.

It turned out that adding some indexes improved the query performance a 
lot. I don't know the details, hopefully others can comment or you can 
find them in the archives.

-- 
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  Daniel Morissette               dmorissette at dmsolutions.ca
  DM Solutions Group              http://www.dmsolutions.ca/
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