[TinyOWS-users] An enhancement for TinyOWS

Rahkonen Jukka Jukka.Rahkonen at mmmtike.fi
Thu Sep 1 23:39:28 EST 2011


That is not supported by WFS standard but I don know some services using such a tailored throttle.  It could perhaps be a useful configuration option in TinyOWS but it would not suit very well for a public WFS because all the users should be aware of such a limit. And what the server would send without any BBOX in the request?

But QGis should really be more clever and not just send plain GetFeatures. Version 1.8.0 has filter option but it is not very user friendly. Look what you can do with Kosmo GIS:

-Jukka Rahkonen-

Andrea Peri wrote:

> Hi,

 > I'm study-ing TinyOWS as server WFS,
using qgis as wfs client.

> I notice a procedural issue when the dataset is huge.

> It need a very much time to startup on first visualization.
The qgis plugin need to download all the dataset.
The only solution to avoid this time lost, is activate the "limit-feature" option.
But it is a strange solution.
Infact the qgis WFS-plugin download the first feature untile the limit set, and after don't show any other dataset.
If I try to zoon to a details if the detail is out of the first downloaded feature, simply qgis show nothing.
Perhaps this is an issue of qgis plugin, but however I guess the "limit-feature" solution for huge dataset is not a
solution in many use-case.

> I guess a better approach should be a
dimension approach.
> Allowing the size in unit of length of the max dataset retrievable.

> something like

<limits unit-of-lenght="1000" />  (dont send when the portion asked is more than a square of 1000x1000 unit-of-lenght)

> For example setting max retrievable size = 1000 meters,
the wfs server should be send data only if the bbox asked has a size under
1000meters x 1000meters

> Without see how much features it could contains.

> Of course this mean to set something like a scale-dependent limitation,
but this in many use-case is more affordable then a limit-features .


Andrea Peri
. . . . . . . . .
qwerty àèìòù

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