[mapserver-dev] msPostGISLayerGetExtent should consider layer filter

[Tamas Szekeres]

I think it would be faster to execute the ST_Extent aggregate on a smaller
set of geometries (though it might depend on the implementation).
The benefit would probably be that LayerGetExtent could be used to
calculate the actual extent of the layer.

Best regards,

Tamas


2018-04-06 9:24 GMT+02:00 Rahkonen Jukka (MML) <
jukka.rahkonen at maanmittauslaitos.fi>:

> Hi,
>
>
>
> What would be the benefits of appending the ”where”? How often the query
> is run and can it be slow?
>
>
>
> -Jukka Rahkonen-
>
>
>
> *Lähettäjä:* mapserver-dev [mailto:mapserver-dev-bounces at lists.osgeo.org] *Puolesta
> *Tamas Szekeres
> *Lähetetty:* 6. huhtikuuta 2018 10:19
> *Vastaanottaja:* mapserver-dev at lists.osgeo.org
> *Aihe:* [mapserver-dev] msPostGISLayerGetExtent should consider layer
> filter
>
>
>
> Hi Devs,
>
>
>
> We would require that msPostGISLayerGetExtent would apply the specified
> filter when calculating the layer extent. This would probably be happen by
> appending the "where" clause from  msPostGISBuildSQLWhere to
> sqlExtentTemplate. Does this make sense?
>
> I've checked the code and some of the drivers consider the filter and some
> are not, so I'm not completely sure about the expected behaviour.
>
>
>
> Best regards,
>
>
>
> Tamas
>
>
>
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