[mapserver-users] MapServer 7.4.3 - Poor projection from British National Grid (EPSG 27700) to WebMercator (EPSG 3857)

[BenH]

I have tried some tests of this.
A simple view, outputting the geometry with ST_Transform, is not
performant at all - the transform breaks the spatial index and it's a
large dataset.
I assume that would still be an issue with a materialized view.
So I think the only PostGIS option would be to create a full copy of the
geometry with its own index. I've tested this, so it is a fall back
option - but it's a lot of data duplication and the Mapserver transform
is really quick.
Thanks

On 06/09/2021 13:38, Mike Saunt wrote:
> Ben
>
> Have you considered using PostGIS to do the transformation instead? 
> Also, depending on the amount of data you could set up some material
> views building transformed data or similar which may make it more
> responsive, if that is needed.
>
> All the best
> Mike