SELECT r_table_name, r_raster_column, out_db FROM raster_columns;
returned the following output:
"test_rast","rast","[True, True, True]"
SELECT t.rid, (md).isoutdb, (md).path
FROM test_rast AS t, ST_BandMetaData(t.rast) AS md
limit 1;
returned the following output:
1,True,"/home/nagispg/local/src/SID_Test/rast_1.sid"
SELECT ST_Width(rast) wdth, ST_Height(rast) hgt
FROM test_rast;
returned the following output:
10000,7000
The "Add to canvas" menu is a pop-up that is displayed when you right-click on the raster table from the DB Manager Menu (Database => DB Manager => DB Manager)