This function clears the specified area of a raster object.


raster ST_EraseOverview(raster raster_obj, Box extent, BoxType type, boolean useNodata); 


Parameter Description
raster_obj The raster object.
extent The area to be cleared, in the format of '((minX,minY),(maxX,maxY))'.
type The coordinate type of the area to be cleared. The value must be Raster or World, where Raster indicates pixel coordinates and World indicates world coordinates.
useNodata Indicates whether to use the predefined NoData value to fill the area to be cleared. If this parameter is set to false or the NoData value is not defined, 0 is used to fill the area.


Select ST_EraseOverview(raster_obj, '((0,0),(100,100))', 'Raster', false) from raster_table where id=100;