17.05 - Usage Notes - Teradata Database

Teradata Vantageā„¢ - Geospatial Data Types

Advanced SQL Engine
Teradata Database
June 2020
Programming Reference

For the MBR calculation, the planet is modeled as a spheroid. If you do not pass in values for the semimajor and invflattening arguments, the computation uses the semimajor axis and the inverse flattening ratio from the World Geodetic System, WGS84. A value of 6,378,137.0 meters is used for the semimajor axis, and a value of 298.257223563 is used for the inverse flattening ratio.

ST_SphericalBufferMBR and ST_SpheroidalBufferMBR perform a similar function, but with different performance and accuracy. ST_SphericalBufferMBR models the earth as a simple sphere, so it performs better than ST_SpheroidalBufferMBR, but with less accuracy. ST_SpheroidalBufferMBR models the earth as a spheroid, so it returns a more accurate MBR, but it runs slower than ST_SphericalBufferMBR.

The returned MBR cannot cross the longitude value of +/-180 or the latitude value of +/-90. The MBR cannot cover more than 180 degrees of latitude or longitude on the sphere or spheroid.