17.10 - Usage Notes - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - Geospatial Data Types

Advanced SQL Engine
Teradata Database
Release Number
Release Date
July 2021
Content Type
Programming Reference
Publication ID
English (United States)

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.