Spatial Operator Functions mysql>  SET @pt = ST_GeomFromText(’POINT(0 0)’); mysql>  SET @pt_strategy = ST_Buffer_Strategy(’point_square’); mysql>  SELECT ST_AsText(ST_Buffer(@pt, 2, @pt_strategy)); +--------------------------------------------+ | ST_AsText(ST_Buffer(@pt, 2, @pt_strategy)) | +--------------------------------------------+ | POLYGON((-2 -2,2 -2,2 2,-2 2,-2 -2)) | +--------------------------------------------+ mysql>  SET @ls = ST_GeomFromText(’LINESTRING(0 0,0 5,5 5)’); mysql>  SET @end_strategy = ST_Buffer_Strategy(’end_flat’); mysql>  SET @join_strategy = ST_Buffer_Strategy(’join_round’, 10); mysql>  SELECT ST_AsText(ST_Buffer(@ls, 5, @end_strategy, @join_strategy)) +---------------------------------------------------------------+ | ST_AsText(ST_Buffer(@ls, 5, @end_strategy, @join_strategy)) | +---------------------------------------------------------------+ | POLYGON((5 5,5 10,0 10,-3.5355339059327373 8.535533905932738, | | -5 5,-5 0,0 0,5 0,5 5)) | +---------------------------------------------------------------+ • ST_Buffer_Strategy( strategy  [,  points_per_circle ]) •For point strategies, permitted values are  ’point_circle’  and  ’point_square’ . •For join strategies, permitted values are  ’join_round’  and  ’join_miter’ . •For end strategies, permitted values are  ’end_round’  and  ’end_flat’ . •If any argument is invalid, an  ER_WRONG_ARGUMENTS  error occurs. •If the first argument is  ’point_square’  or  ’end_flat’ , the  points_per_circle  argument must not be given or an  ER_WRONG_ARGUMENTS  error occurs. • ST_ConvexHull( g ) 2320 This function computes a geometry’s convex hull by first checking whether its vertex points are colinear. The function returns a linear hull if so, a polygon hull otherwise. This function processes geometry Returns a geometry that represents the convex hull of the geometry value  g . ST_Buffer_Strategy()  handles its arguments as described in the introduction to this section, with these exceptions: For examples, see the description of  ST_Buffer() . If the first argument is  ’point_circle’ ,  ’join_round’ ,  ’join_miter’ , or  ’end_round’ , the  points_per_circle  argument must be given as a positive numeric value. The maximum points_per_circle  value is the value of the  max_points_in_geometry  system variable. The first argument must be a string indicating a strategy option: Information about strategies is available at Boost.org. This function returns a strategy byte string for use with  ST_Buffer()  to influence buffer computation.