Example: Tessellate Search Function

Teradata Vantage™ Geospatial Data Types

Teradata Database
Teradata Vantage NewSQL Engine
Programming Reference
CREATE TABLE sample_cities(
 skey INTEGER, cityName VARCHAR(200), cityShape ST_Geometry);

INSERT INTO sample_cities values(
 1067, New ST_Geometry('Polygon(
  (-43.5 20.2, -43.5 21.5, -40.5 21.5, -40.5 20.2, -43.5 20.2))'));

Consider the data in the cities_index table that is inserted using the Tessellate_Index method:

CREATE TABLE cities_index
   (skey INTEGER
   ,cellid INTEGER);

INSERT INTO cities_index
SELECT skey,
   cityShape.Tessellate_Index(-180, 0, 0, 90, 500, 500, 1, 0.01, 0)
FROM sample_cities;

The following statement uses the Tessellate_Search function with the same universe coordinates and grid specifications that were used by Tessellate_Index:

SELECT c.skey, c.cityName, s.streetName, s.streetShape
FROM sample_cities c
    ,cities_index ci
    ,(SELECT streetName, skey, streetShape ,streetShape.ST_MBR_Xmin()
            ,streetShape.ST_MBR_Ymin(), streetShape.ST_MBR_Xmax()
      FROM sample_streets)
      AS s (streetName, skey, streetShape, xmin, ymin, xmax, ymax)
    ,TABLE ( Tessellate_Search (
               ,s.xmin, s.ymin, s.xmax, s.ymax
               ,-180, 0, 0, 90
               ,1, 0.01, 0)) AS t
WHERE c.skey = ci.skey
AND ci.cellid = t.cellid
AND t.out_key = s.skey;