On 10-9-2013 21:36, Rob Warren wrote:
Frans,
The nice thing about a sparql server is that you get what you ask for. If you want only
the "Feature" without the geometry, you can do that. If you only want whatever
centroid the Feature is linked to, you can do that. If you want everything, you can do
that. At worst, you can 'count' the length of the literal or the number of points to give
you an idea of the number of coordinates present.
I'm not completely happy with the opengis literals myself, but realize that
with basic sparql you can strip the coordinates to the bare numerical
information (no uri's) and send it in json to the client. Add to this transport
level compression (web-server's problem) and things are as fast as can be
expected for any remote storage situation.
Do you mean HTTP compression
<http://en.wikipedia.org/wiki/HTTP_compression>? Thank you for bringing
that to my attention. I was not aware that such a thing existed. I will
put it on my list of things to investigate. For example, I wonder if it
is commonly supported in Linked Data clients and servers.
You will never compete with a local drive with a binary representation.
best,
rhw
On 2013-09-10, at 4:09 PM, Frans Knibbe | Geodan wrote:
The problem that I see is how to handle those cases where geometry literals
become unwieldy. The GeoSparql specification that you mention provides a way of
writing a geometry as a literal in RDF. There may be several approaches as to
how to serialize a geometry, but ending up with series of coordinates is
inescapable. And I am worried about the impact of these series of coordinates
becoming very long. That is why I also do like the idea of providing some extra
data to enable a client to distinguish between large and small geometries. The
small ones could be downloaded and processed right away, but the bigger ones
might need some extra care.
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