Andrea, thanks for your detailed answer

>
> And keep it in memory? It may work on a desktop or a batch software,
> where you have all the heap for yourself, but in a server where you
> have hundreds of concurrent requests it's a recipe for OOM.

No, I did not meant storing in memory. I was just trying to know if
that solution you propose was somehow already into Geotools so,
although it looks it recalculates everything, it does not since there
is some kind of smart cache somewhere. I am no expert on geotools, but
(and I know I might be asking too much :-) ) , from the point of view
of a process developer, the ideal thing would be to tell Geotools that
you are going to create a new FeatureCollection...and let it take care
of how it deals with the amout of data. Unfortunately, most of the
people (like myself) creating geoprocesses do know about the
foundations of spatial data analysis and their interpretation...but
lack the knowledge that people like you have about data handling and
storage, or server technologies :-(

Since you mention JAI, I have been looking at the code of some raster
algorihtms, and whether they create the data array in memory (bad
recipe, as you said...), or they rely in JAI. Is there no way of
creating a raster layer and populate it yourself with the result of
your process (written in your geotools process without needing to add
some process to JAI), and letting Geotools handle the internal
complexity of storing the data?

In other words (and in my ideal day-dreaming world of a geoprocess
developer...),creating a raster layer for, let's say, a process
calculating slope from a DEM, should be done the same way whether the
final result is a 10x10 tiny raster or one with a trillion cells.
Internally, Geotools would work in a completely different manner. From
the outside, however, it would be the same. I should focus on the
slope algorithm (which is what I know about...), not the
caching/tiling/heap space limits, etc... The underlying library
(Geotools in this case) will do it.

Once again, I know that I am asking too much, and that the complexity
of what I am asking for is enormous :-)

In short, for raster processes, which is your recommendation? Should I
use JAI then?

Many thanks in advance!

Victor

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