Re: [gdal-dev] Performance Issue with VRT Pixel Function and Large Number of Source Rasters

Hi, I got interested in trying what if all the images overlap totally. The timings from my test looks good to me, 28 seconds for creating a max raster from 1000 single band rasters, 1000x1000 pixels each. However, I am not totally sure if my test is valid so I present it here. First create 10

Re: [gdal-dev] Performance Issue with VRT Pixel Function and Large Number of Source Rasters

Hi, When "max" pixel function is used then GDAL needs to analyze every single pixel from every overlapping image for finding out the maximum values. Without pixel functions there is nothing to analyze but the pixels from the last image in a pile will beat all the previous pixels. I would try

Re: [gdal-dev] Performance Issue with VRT Pixel Function and Large Number of Source Rasters

Laurentiu, Bumping GDAL_MAX_DATASET_POOL_SIZE did not make any difference for me. My source rasters are of different block sizes but they are relatively small. As you have noted, the drastic performance differen

Re: [gdal-dev] Performance Issue with VRT Pixel Function and Large Number of Source Rasters

Hi, Some previous discussion about the same thing in https://gis.stackexchange.com/questions/491309/performent-way-of-merging-multiple-rasters-into-a-single-cog-gtiff-with-gdal-w? With untiled images it is not a surprise that small -projwin does not have a great effect. But with 1000x1000 pixel

Re: [gdal-dev] Performance Issue with VRT Pixel Function and Large Number of Source Rasters

Hi Abdul, Can you bump https://gdal.org/en/stable/user/configoptions.html#config-GDAL_MAX_DATASET_POOL_SIZE and see if it helps? And do all inputs have the same block size of 1048x7? Ideally, your inputs and output will all have the same block size or a multiple of it, so you could also add -c