In Oracle PL/SQL, SDO_CS is a package which is owned by MDSYS user. It is used to implement Co-ordinate Transformation functions on single or complete layer of geometry.
The subprograms contained in the SDO_CS package are as described below:
SDO_CS.TRANSFORM: Transforms a geometry representation for given SRID using a coordinate system.
SDO_CS.TRANSFORM_LAYER: Transforms an entire layer of geometries.
SDO_CS.VIEWPORT_TRANSFORM: Transforms a rectangle into a polygon to be used with spatial operators and functions.
The subprograms make use of the SDO_GEOMETRY data type, which is also owned by MDSYS.