The spatial reference system identifies the coordinate transformation for each geometry.
All spatial reference systems known to the database can be accessed through the DB2GSE.SPATIAL_REF_SYS catalog view. For information about this view, see Catalog views.
The ST_SRID function takes a geometry and returns its spatial reference identifier as an integer. For more information, see ST_SRID.
The ST_Transform function assigns a geometry to a spatial reference system other than the spatial reference system to which the geometry is currently assigned. For more information, see ST_Transform.