ST_Distance(g1,g2)
Calculates the shortest distance between two spatial objects.The distance is measured in degrees.
Parameters
| Parameter | Type | Description |
|---|---|---|
g1 |
Geometry |
The spatial location of the first location defined using the WKT notation |
g2 |
Geometry |
The spatial location of the second location defined using the WKT notation |
Returns
double
Example
SELECT *
FROM geospock.default.largetable AS large,
geospock.default.smalltable AS small
WHERE ST_Distance(ST_Point(small.longitude, small.latitude), ST_Point(large.longitude, large.latitude)) < small.radius;
Usage
To define a geofence using ST_Distance(), your query will look like this:
SELECT *
FROM geospock.default.largetable AS large,
geospock.default.smalltable AS small
WHERE ST_Distance(ST_Point(small.longitude, small.latitude), ST_Point(large.longitude, large.latitude)) < 0.0005;
Note that this will return a distance in degrees.
If you are using a Hive table to provide the locations of the POIs, the relevant fields in that
able must be named latitude and longitude in order for the optimization to take place. In
addition, the fields must be of type double, decimal or float/real.