Return the smallest distance ever

{geo,cbuffer,tcbuffer} |=| {geo,cbuffer,tcbuffer} → float

The operator |=| that can be used for doing nearest neightbor searches using a GiST or an SP-GiST index (see the section called “Indexing”).

SELECT tcbuffer '[Cbuffer(Point(2 2), 0.3)@2001-01-01,
  Cbuffer(Point(2 2), 0.7)@2001-01-02]' |=| geometry 'Linestring(50 50,55 55)';
-- 67.58225099390856
SELECT tcbuffer '[Cbuffer(Point(2 2), 0.3)@2001-01-01,
  Cbuffer(Point(2 2), 0.7)@2001-01-02]' |=| cbuffer 'Cbuffer(Point(1 1), 0.5)';
-- 0.6142135623730951

TODO Return the instant of the first temporal circular buffer at which the two arguments are at the nearest distance

nearestApproachInstant({geo,cbuffer,tcbuffer},{geo,cbuffer,tcbuffer}) → tcbuffer

SELECT nearestApproachInstant(tcbuffer '[Cbuffer(Point(2 2), 0.3)@2001-01-01,
  Cbuffer(Point(2 2), 0.7)@2001-01-02]', geometry 'Linestring(50 50,55 55)');
-- Cbuffer(Point(2 2),0.349928)@2001-01-01 02:59:44.402905+01
SELECT nearestApproachInstant(tcbuffer '[Cbuffer(Point(2 2), 0.3)@2001-01-01,
  Cbuffer(Point(2 2), 0.7)@2001-01-02]', cbuffer 'Cbuffer(Point(1 1), 0.5)');
-- Cbuffer(Point(2 2),0.592181)@2001-01-01 17:31:51.080405+01

TODO Return the line connecting the nearest approach point between the two arguments

shortestLine({geo,cbuffer,tcbuffer},{geo,cbuffer,tcbuffer}) → geometry

The function will only return the first line that it finds if there are more than one

SELECT ST_AsText(shortestLine(tcbuffer '[Cbuffer(Point(2 2), 0.3)@2001-01-01,
  Cbuffer(Point(2 2), 0.7)@2001-01-02]', geometry 'Linestring(50 50,55 55)'));
-- LINESTRING(50 50,2.212132034355964 2.212132034355964)
SELECT ST_AsText(shortestLine(tcbuffer '[Cbuffer(Point(2 2), 0.3)@2001-01-01,
  Cbuffer(Point(2 2), 0.7)@2001-01-02]', cbuffer 'Cbuffer(Point(1 1), 0.5)'));
-- LINESTRING(1.353553390593274 1.353553390593274,1.787867965644036 1.787867965644036)

TODO Return the temporal distance

{geo,cbuffer,tcbuffer} <-> {geo,cbuffer,tcbuffer} → tfloat

SELECT tcbuffer '[Cbuffer(Point(1 1), 0.3)@2001-01-01, 
  Cbuffer(Point(1 1), 0.5)@2001-01-03]' <-> cbuffer 'Cbuffer(Point(1 1), 0.2)';
-- [2.34988300875063@2001-01-02 00:00:00+01, 2.34988300875063@2001-01-03 00:00:00+01]
SELECT tcbuffer '[Cbuffer(Point(1 1), 0.3)@2001-01-01, 
  Cbuffer(Point(1 1), 0.5)@2001-01-03]' <-> geometry 'Point(50 50)';
-- [25.0496666945044@2001-01-01 00:00:00+01, 26.4085688426232@2001-01-03 00:00:00+01]
SELECT tcbuffer '[Cbuffer(Point(1 1), 0.3)@2001-01-01, 
  Cbuffer(Point(1 1), 0.5)@2001-01-03]' <->
  tcbuffer '[Cbuffer(Point(1 1), 0.3)@2001-01-02, Cbuffer(Point(1 1), 0.5)@2001-01-04]'
-- [2.34988300875063@2001-01-02 00:00:00+01, 2.34988300875063@2001-01-03 00:00:00+01]