Devuelve la distancia más cercana

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

El operador |=| se puede utilizar para realizar búsquedas del vecino más cercano utilizando un índice GiST o SP-GiST (ver “Indexación”).

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

Devuelve el instante del primer búfer circular temporal en el que los dos argumentos están a la distancia más cercana

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
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

Devuelve la línea que conecta el punto de aproximación más cercano entre los dos argumentos

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

La función devuelve la primera línea que encuentre si hay más de una

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)

Devuelve la distancia temporal

{geo,cbuffer} <-> tcbuffer → tfloat
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)';
-- [0@2001-01-01, 0@2001-01-03]
SELECT tcbuffer '[Cbuffer(Point(1 1), 0.3)@2001-01-01,
  Cbuffer(Point(1 1), 0.5)@2001-01-03]' <-> geometry 'Point(50 50)';
-- [68.99646455628167@2001-01-01, 68.79646455628166@2001-01-03]
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]';
-- [0@2001-01-02, 0@2001-01-03]