@(geometry,box2df) — Returns TRUE if a geometry's 2D bounding box is contained into a 2D float precision bounding box (BOX2DF).
boolean @( geometry  A ,  box2df  B );
The @ operator returns TRUE if the A geometry's 2D bounding box is contained the 2D bounding box B, using float precision. This means that if B is a (double precision) box2d, it will be internally converted to a float precision 2D bounding box (BOX2DF)
                 
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                 This operand is intended to be used internally by BRIN indexes, more than by users.  | 
            
Availability: 2.3.0 support for Block Range INdexes (BRIN) was introduced. Requires PostgreSQL 9.5+.
            
 Questo metodo supporta le Curve e le Circular String. 
            
 Questa funzione supporta le Polyhedral Surface. 
SELECT ST_Buffer(ST_GeomFromText('POINT(2 2)'), 1) @ ST_MakeBox2D(ST_Point(0,0), ST_Point(5,5)) AS is_contained;
 is_contained
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 t
(1 row)