ST_BoundingDiagonal
Name
ST_BoundingDiagonal — Returns the diagonal of the supplied geometry's bounding box.
Synopsis
    
     geometry
     
      ST_BoundingDiagonal
     
     (
    
    geometry
    
     geom
    
    , boolean
    
     fits=false
    
    
     )
    
    ;
   
Description
Returns the diagonal of the supplied geometry's bounding box as linestring. If the input geometry is empty, the diagonal line is also empty, otherwise it is a 2-points linestring with minimum values of each dimension in its start point and maximum values in its end point.
The returned linestring geometry always retains SRID and dimensionality (Z and M presence) of the input geometry.
   The
   
    fits
   
   parameter specifies if the best fit is needed.
If false, the diagonal of a somewhat larger bounding box can be accepted
(is faster to obtain for geometries with a lot of vertices). In any case
the bounding box of the returned diagonal line always covers the input
geometry.
  
       
      | 
     |
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       In degenerate cases (a single vertex in input) the returned linestring will be topologically invalid (no interior). This does not make the return semantically invalid.  | 
    
Availability: 2.2.0
   
    
   
   This function supports 3d and will not drop the z-index.
  
   
    
   
   This function supports M coordinates.