[mapserver-users] Help in plotting several tens of thousand 'pies'

[Arun Cherian]

Hello,

I was hoping the experience of the members here would help in something I
was researching. A bit of background. We have cellular data for wireless
operators in a DB. The data is referred to as a 'System' and consists of
around 50k 'sites' and each site has 3 or more 'cells' on it. It would in a
map perspective look like a small circle with several pies around it. So
all in all looking at a few hundred thousand polygons to plot. We used to
serve this data as a vector for smaller systems via GeoJSON and use
Openlayers 2 to render on a slippery map. For a few hundred sites it was
fine, no performance degradation or issues. When we started testing with
larger real life samples, the browser would literally crawl. I understand
it is because each vector feature adds to the DOM and there is a limit. We
have used mapserver to provide an OSM map for our base layer, and I was
thinking of serving the system vector data as raster/tiles. A few questions
I have are below.Apologies for the long post. Any comment appreciated.

1. Is there a way to easily draw a pie? We store center, azimuth and other
'metadata' for the pie in the DB and create a polygon on the fly in
Openlayers, is there a faster way to do it in mapserver when creating the
raster?

2. Vector features can be 'clicked' or selected, can the same be done for
raster layers, so we know which site/cell is selected? Based on the site
clicked, we fetch data from another DB table to open a popup.

3. Client side users have the option to apply their own coloring scheme to
the pies, how would that be done at the server side, sending a request for
re-rendering the pies? Would this create a scenario where several users hit
the server with a lot of re-render requests?

Is this the right way to go about it? A lot of the neat features of vectors
are because all the data is readily available on the client side, but that
is also the reason for the performance hit when we load a few thousand
sites via GeoJSON.

Thanks,
Arun
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