[mapserver-users] MapInfo "Seamless" layer performance issues

[Daniel Morissette]

Hi Dan,

The performance issue that you noticed is not normal, so I have filed a
bug about this http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=164 

Can you please add to the bug report your configuration information:
MapServer/MapScript version, OS, GDAL/OGR version to help us reproduce
it?

Thanks,

Daniel


"Martin, Daniel" wrote:
> 
> I'm trying to use MapInfo Seamless layers in MapServer.  They do work, which
> is great.  But they are slow relative to the individual layers.  To
> elaborate, I have one Postal Code layer per state.  To treat them as a
> single layer for a National mapping application, I have created a "Seamless"
> layer to pull them all together.
> 
> Now, I expect that to be slow.  Even pulling it into MapInfo is slow.  It's
> a huge amount of data.  However, if I zoom in to a scale of a few miles, I
> should only be loading one layer because I can only see one state.  But even
> this is very slow.  If I load the same map using the actual physical layer
> rather than the seamless, it's pretty fast, even though it's displaying the
> same data.  Even if I merge the entire national Postal Code dataset into one
> gigantic layer, it performs fairly fast, so the issue cannot be in the
> volume of data.  Specifically this last example doesn't seem to make sense.
> And the performance difference is minutes as opposed to seconds, Seamless
> vs. normal.
> 
> Is there something I can do to improve performance of a Seamless layer?  Or
> is it just a reality, and I should look to combining my data.
> 
> Thanks,
> Dan Martin