Returns the ST_Geometry value that represents all points whose distance from any point of an ST_Geometry value is less than or equal to a specified distance in the given units.
      Syntax
         
            geometry-expression.ST_Buffer(DOUBLE distance, VARCHAR(128) unit_name)
      
      Parameters
         
            - 
               distance – 
               The distance the buffer should be from the geometry value.
            
- 
               unit_name – 
               The units in which the distance parameter should be interpreted. Defaults to the unit of the spatial reference system. The unit name must match the UNIT_NAME column of a row in the ST_UNITS_OF_MEASURE view where UNIT_TYPE is 'LINEAR'.
            
Returns
         ST_Geometry Returns the ST_Geometry value representing all points within the specified distance of the geometry-expression.
      Standards
         
            SQL/MM (ISO/IEC 13249-3: 2006) 5.1.17