How to use ST_fromGDALRaster correctly with a given GeoTIFF

I am trying to import gdal raster data (a GeoTIFF) to a Postgis database, using the ST_FromGDALRaster method (http://postgis.net/docs/manual-2.1/RT_ST_FromGDALRaster.html).

The question is that I don’t know the correct declaration of the gdaldata (bytea) parameter in the SQL statement and if there are examples given showing this. Trying simple path names does not work.

I know the other possibility of loading rasters into postgis db using the ‘raster2pgsql’ excecutable, but this way will not work with memory rasters in GDAL.

Thanks