ST_ScaleY — Returns the Y component of the pixel height in units of coordinate reference system.
float8 ST_ScaleY(raster rast);
Returns the Y component of the pixel height in units of coordinate reference system. May be negative. Refer to World File for more details.
Changed: 2.0.0. In WKTRaster versions this was called ST_PixelSizeY.
SELECT rid, ST_ScaleY(rast) As rastpixheight
FROM dummy_rast;
rid | rastpixheight
-----+---------------
1 | 3
2 | -0.05