[OpenLayers-Users] Cluster strategy but on the server
Yves Moisan
yves.moisan at boreal-is.com
Mon Apr 6 08:27:01 EDT 2009
> For my needs I have come up with this:
>
> * A separate table for the cluster features, with columns
> for the geometry (a point), a feature count and the scale
> (i.e. I store the cluster points for all scales in one
> table)
>
> * A view for each scale
>
> "create view cluster_1M as select * from clusters where scale = 1000000"
>
> etc.
>
> * A stored procedure which runs the same clustering algorithm
> as OpenLayers.Strategy.Cluster on the original spatial table
> and adds the clusters in the cluster table.
>
> * Then I'll set up the layers and scale limits so that the
> cluster layer for each scale is dispalyed for that scale
> only.
>
> * I'll probably add a trigger on the original spatial table
> and add each single new point to the clusters rather than
> have to regenerate the whole thing.
>
> The backend is Oracle Spatial (10.2).
Pretty much what I need too and the sort of thing we were thinking of.
There definitely is a need to avoid treating features as images when
there are too many of them. Thanx for sharing your design.
Yves
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