unionarg — A composite type used as input into the ST_Union function defining the bands to be processed and behavior of the UNION operation.
A composite type used as input into the ST_Union function defining the bands to be processed and behavior of the UNION operation.
nband
integer
1-based value indicating the band of each input raster to be processed.
uniontype
text
Type of UNION operation. One of defined types as described in ST_Union.