ST_RemovePoint() - ZM
:memory: #use in-memory database
SELECT AsText(RemovePoint(GeomFromText('LINESTRINGZM(0 0 1 2, 1 0 2 3, 1 1 3 4)'), 1))
1 # rows (not including the header row)
1 # columns
AsText(RemovePoint(GeomFromText('LINESTRINGZM(0 0 1 2, 1 0 2 3, 1 1 3 4)'), 1))
LINESTRING ZM(0 0 1 2, 1 1 3 4)