ApsaraDB RDS:ST_{X|Y|Z|T}Max

Syntax

float8 ST_XMax(boxndf box);
float8 ST_YMax(boxndf box);
float8 ST_ZMax(boxndf box);
timestamp ST_TMax(boxndf box);

Parameters

Description

This function allows you to query the maximum value of a bounding box in a specified dimension.

• If the bounding box does not have the specified x, y, or z dimension, this function returns NaN.

• If the bounding box does not have the specified t dimension, this function returns -infinity.

Example

select ST_tmax(ST_MakeBox2dt(0,0,'2000-01-01'::timestamp, 20,20, '2020-01-01'::timestamp));
       st_tmax       
---------------------
 2020-01-01 00:00:00

select ST_zmax(ST_MakeBox2dt(0,0,'2000-01-01'::timestamp, 20,20, '2020-01-01'::timestamp));
 st_zmax 
---------
     NaN

select ST_tmax(ST_MakeBox2d(0,0, 20,20));
  st_tmax  
-----------
 -infinity