Performance(?) issues with ST_Reskew() (on rasters)

[Frank Gevaerts]

Hello,

I'm having issues with ST_Reskew(). The source raster (32BSI) contains 150000 points, and ST_Reskew() takes forever. If I rescale the raster to anywhere under ~80000 points, it suddenly only takes around 300ms. This is not linear, ~85000 points is bad, and then suddenly 80000 points is good.

I'm not actually sure if it's "just" a performance problem or an infinite loop, I have not had the patience yet to have it run for more than 20 minutes.

This is using postgis 3.5.2 on debian installed from apt.postgresql.org, and libgdal36 3.10.2

Is there anything I'm overlooking, or is there a memory usage parameter I can set to help with this?

Frank