1ST_Perimeter - Linestring  (Long/Lat metric - GreatCircle)
2:memory: #use in-memory database
3SELECT ST_Perimeter(GeomFromText('LINESTRING(0.7 0.7, 0.7 0.8, 0.8 0.8, 0.8 0.7, 0.7 0.8)'), 0);
41 # rows (not including the header row)
51 # columns
6ST_Perimeter(GeomFromText('LINESTRING(0.7 0.7, 0.7 0.8, 0.8 0.8, 0.8 0.7, 0.7 0.8)'), 0)
70.0
8