DropRasterConstraints — Drops PostGIS raster constraints that refer to a raster table column. Useful if you need to reload data or update your raster column data.
boolean DropRasterConstraints(name 
			rasttable, name 
			rastcolumn, boolean 
			srid, boolean 
			scale_x, boolean 
			scale_y, boolean 
			blocksize_x, boolean 
			blocksize_y, boolean 
			same_alignment, boolean 
			regular_blocking, boolean 
			num_bands=true, boolean 
			pixel_types=true, boolean 
			nodata_values=true, boolean 
				out_db=true
			, boolean 
			extent=true);
boolean DropRasterConstraints(name 
			rastschema, name 
			rasttable, name 
			rastcolumn, boolean 
			srid=true, boolean 
			scale_x=true, boolean 
			scale_y=true, boolean 
			blocksize_x=true, boolean 
			blocksize_y=true, boolean 
			same_alignment=true, boolean 
			regular_blocking=false, boolean 
			num_bands=true, boolean 
			pixel_types=true, boolean 
			nodata_values=true, boolean 
				out_db=true
			, boolean 
			extent=true);
boolean DropRasterConstraints(name 
			rastschema, name 
			rasttable, name 
			rastcolumn, text[] 
			constraints);
Drops PostGIS raster constraints that refer to a raster table column that were added by AddRasterConstraints. Useful if you need to load more data or update your raster column data. You do not need to do this if you want to get rid of a raster table or a raster column.
To drop a raster table use the standard
DROP TABLE mytable
To drop just a raster column and leave the rest of the table, use standard SQL
ALTER TABLE mytable DROP COLUMN rast
the table will disappear from the raster_columns catalog if the column or table is dropped.  However if only the constraints are dropped, the
		raster column will still be listed in the raster_columns catalog, but there will be no other information about it aside from the column name and table.
Availability: 2.0.0
SELECT DropRasterConstraints ('myrasters','rast');
----RESULT output ---
t
-- verify change in raster_columns --
SELECT srid, scale_x, scale_y, blocksize_x, blocksize_y, num_bands, pixel_types, nodata_values
	FROM raster_columns
	WHERE r_table_name = 'myrasters';
 srid | scale_x | scale_y | blocksize_x | blocksize_y | num_bands | pixel_types| nodata_values
------+---------+---------+-------------+-------------+-----------+-------------+---------------
    0 |         |         |             |             |           |             |