<span class="Apple-style-span" style="font-family: verdana, geneva, helvetica, arial, sans-serif; font-size: 13px; border-collapse: collapse; "><div><span class="Apple-style-span" style="font-family: verdana, geneva, helvetica, arial, sans-serif; font-size: 13px; border-collapse: collapse; ">And the topic is: Raster Strategies Example</span></div>
<div><span class="Apple-style-span" style="font-family: verdana, geneva, helvetica, arial, sans-serif; font-size: 13px; border-collapse: collapse; "><br></span></div>I have read many strategies for raster performance, but i still have problems with my case. The posts that i have read explain the strategie, but are not very detailed. Im new to mapserver so i have problems implementing them. My case is: <br>
<br>-about 6000 tiles that form the map <br>-170mb each tile <br>-aproximately 1.2T of iamges <br>-i have 10T HD and i think disk space is not a problem for me <br>-tile format is TIF <br>-tile size 9375x6250 pixels <br><br>
The strategy i have implemented and the problems i have <br><br>-First i divided the tiles in 60 folders, to increase the performance in disk seek/read. <br><br>-Than i transformed source files into internally tiles with the command <br>
gdal_translate -of GTiff -co "TILED=YES" original.tif tiled.tif <br><br>-i used gdaladdo to add internal pyramids <br><br> gdaladdo -r average 2 4 8 16 32 64 128 <br><br>-Created a tileindex using <br> gdaltindex -write_absolute_path MapAll.shp //server/Maps/Subfolder1/*.tif <br>
<br>-Created a spatial index .qix file <br> shptree MapAll.shp <br><br>-than added the layer to the mapfile without the .shp extension so the application can use the .qix <br><br>as you may know, i have very slow performance when i zoom out and im stucked here. As i have read i should make a copy of the tiles with reduced resolution. Merge the tiles together and use min/max scale to show different layers in different scales. the min/max scales i zoom in/out are 100/1200000. Now my questions are <br>
<br>- How can i calculate the scale where i should create another layer of the tiles, or i shoud see it with some tests? <br><br>- how much should be the resolution of the new layer? <br><br>- is there any tools or program to merge the tiles? merging 6000 tiles with the gdalwarp by writing the command by myself is frustrating <br>
<br>- how many tiles should i merge together to create the new layer? (how many tiles should have the new layer) i know that in each zoomscale its better to appear only one tile but i dont know how to calculate it <br><br>
- the tiles that i should merge are the originals or those with internal tiling and overviews? </span>