[mapserver-users] Re: Raster Strategies Examples

[Frank Warmerdam]

Edi.Karadumi wrote:
> Thanx to you my questions are comming to an end  
> 
> Three more last things
> 
> Should i retile the new mosaiced overview? Meaning should i create smaller
> size tiles of the new mosaic? or 2Gb is not a problem

Edi,

Generally speaking, as long as you enable internal tiling when building
the mosaic there is no need to break it down into separate files.
Add '-co TILED=YES' to the gdal_merge.py command to produce an output
GeoTIFF file that is internally tiled.

> And how can i find in which scale should i switch layers? So what will be
> the maxscale of the original layer?

That remains a complicated question.  I believe I suggested 1/32 as a
good overview level since beyond that point a normal map view will tend
to involve a significant number of files.

> if ill still have performance problems, or ill get 1-2 terabytes of data
> more should i make another mosaic with 0.08*16 or 0.08*8, or is there
> another strategy?

I presume as you add data, your area is growing.  If that is so, the 1/32nd
overview level is still appropriate, and you just need to regenerate the
overview for the larger area.

If you are using MapServer and GDAL then there is no real problem with using
one large geotiff file for the overview as long as it has internal tiling,
even if it grows to many GB in size.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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