id summary reporter owner description type status priority milestone component version resolution keywords cc 3483 Problem with ST_Union krzysiek Bborie Park " I have loaded some rasters into Postgis. I did a lot of ST_XXXX (scale, snap to grid,resample) magic to make them aligned. After executing: select r1.rid,r2.rid ,ST_NotSameAlignmentReason(r1.rast,r2.rast) ,ST_SameAlignment(r1.rast,r2.rast) from rasters.r r1, rasters.r r2 where not ST_SameAlignment(r1.rast,r2.rast) I got nothing, if I remove: where not ST_SameAlignment(r1.rast,r2.rast) all I got is ""The rasters are aligned"" Which seems ok, but when I execute: SELECT ST_Union(rast,'FIRST') from rasters.r I got: rt_raster_from_two_rasters: The two rasters provided do not have the same alignment Why ? Postgres 9.4 ""POSTGIS=""2.1.8 r13780"" GEOS=""3.5.0-CAPI-1.9.0 r4090"" PROJ=""Rel. 4.8.0, 6 March 2012"" GDAL=""GDAL 1.11.1, released 2014/09/24"" LIBXML=""2.7.8"" LIBJSON=""UNKNOWN"" RASTER"" " defect closed blocker PostGIS 2.5.0 raster 2.1.x wontfix ST_Union, raster, alignment kmatuk@…