I need to make some calculations with data from raster files saved in my postgis database. I need, build a map, using the average from a set of these raster files, for example.

Besides, I need to make others similar operations like the max value of a set of rasters, among others.

I did'nt see nothing to do operations like it directly on PostGIS (http://postgis.net/docs/manual-2.1/RT_reference.html), there are functions to do it? Besides, I'm worried with the performance, because if I have a lot of raster files, maybe can be better solve these calculations with R, by example, or not?

Thanks

I need to make some calculations with data from raster files saved in my postgis database. I need, build a map, using the average from a set of these raster files, for example.

Besides, I need to make others similar operations like the max value of a set of rasters, among others.

I did'nt see nothing to do operations like it directly on PostGIS (http://postgis.net/docs/manual-2.1/RT_reference.html), there are functions to do it? Besides, I'm worried with the performance, because if I have a lot of raster files, maybe can be better solve these calculations with R, by example, or not?