不同SDE GeoSQL构造函数的效率问题

今天有问题咨询了一下几个SDE For Oracle函数的效率比较问题：
问题如下： SDE提供了 ST_LineString、ST_Point、ST_PolyFromText几个函数来进行点，线，面的构建，同时也提供了 ST_Geometry函数进行点线面的构建，这些函数的功能都是相同的，到底谁的效率更好。
初步判断：
从字面上看ST_LINESTRING，ST_POINT应该是ST_GEOMETRY的子类，以我对ESRI研发人员的风格了解，应该不会每个函数使用不同的算法，这些对象应该最终都会指向同一个函数，也就是说效率是一样的，下面我们可以查看一下源码验证一下。
查看ST_LINESTRING是怎么定义的

SQL> select text from user_source where name='ST_LINESTRING' and type='TYPE BODY';



TEXT --------------------------------------------------------------------------------

Type Body st_linestring AS constructor Function st_linestring(geom_str clob,srid number)

 Return self AS result

 IS

 temp varchar2(1);

 tempraw raw(1);

 entity number;

 geom_type number;

 name varchar2(32);

 spref_r SDE.spx_util.spatial_ref_record_t;



TEXT --------------------------------------------------------------------------------

 shape SDE.st_geom_util.shape_r;

 is_empty boolean := False;

 rc number;

 buffer clob;



 Begin



 geom_type := SDE.st_geom_util.unspecified_type;

 buffer := geom_str;

 SDE.st_geom_util.get_type(buffer,entity,geom_type,is_empty,SDE.st_geom_util.l

inestring_type); TEXT --------------------------------------------------------------------------------





 If entity = SDE.st_geom_util.sg_illegal_shape THEN

 raise_application_error (SDE.st_type_util.st_geometry_invalid_type,'Invalid

 ST_Linestring type.');



 End If;



 SDE.st_geom_util.get_name(entity,name);



 If name != 'LINESTRING' THEN



TEXT --------------------------------------------------------------------------------

 raise_application_error (SDE.st_type_util.st_geometry_invalid_type,'ST_Line

string must use a LINESTRING type.');  End If;



 spref_r.srid := srid;

 rc := SDE.st_spref_util.select_spref(spref_r);

 If rc != SDE.st_type_user.se_success THEN

 raise_application_error (SDE.st_type_util.st_no_srid,'srid '||spref_r.srid||







TEXT --------------------------------------------------------------------------------

 ' does not exist in st_spatial_references table.');





 End If;



 shape.points := empty_blob();

 shape.numpts := 0;

 shape.entity := 0;

 shape.minx := 0;

 shape.miny := 0;

 shape.maxx := 0;



TEXT --------------------------------------------------------------------------------

 shape.maxy := 0;

 shape.area := 0;

 shape.len := 0;

 shape.minz := NULL;

 shape.maxz := NULL;

 shape.minm := NULL;

 shape.maxm := NULL;



 temp := lpad('a', 1, 'a');

 tempraw := utl_raw.cast_to_raw (temp);

 shape.points := tempraw;



TEXT --------------------------------------------------------------------------------



 If is_empty = False THEN

 SDE.st_geometry_shapelib_pkg.geometryfromtext(buffer,spref_r.srid,spref_r.x

_offset,spref_r.y_offset,spref_r.xyunits,



 spref_r.z_offset,spref_r.z_sc

ale,spref_r.m_offset,spref_r.m_scale,



 spref_r.Definit

hape.minx,shape.miny,





TEXT --------------------------------------------------------------------------------

 shape.maxx,shap

hape.maxm,shape.area,shape.len,



 shape.points);

 ELSE

 shape.numpts := 0;

 If geom_type > SDE.st_geom_util.unspecified_type Then

 shape.entity := geom_type;

 else

 shape.entity := 0;

 end if;



TEXT --------------------------------------------------------------------------------

 shape.minx := 0;

 shape.miny := 0;

 shape.maxx := 0;

 shape.maxy := 0;

 shape.minz := NULL;

 shape.maxz := NULL;

 shape.minm := NULL;

 shape.maxm := NULL;

 shape.area := 0;

 shape.len := 0;

 shape.points := empty_blob();



TEXT --------------------------------------------------------------------------------

 shape.srid := srid;

 End If;



 if(shape.numpts IS NULL and shape.entity = 0) then

 self.entity := shape.entity;

 self.numpts := 0;

 self.minx := 0;

 self.maxx := 0;

 self.miny := 0;

 self.maxy := 0;

 self.minz := NULL;



TEXT --------------------------------------------------------------------------------

 self.maxz := NULL;

 self.minm := NULL;

 self.maxm := NULL;

 self.srid := srid;

 else

 self.entity := shape.entity;

 self.numpts := shape.numpts;

 self.minx := shape.minx;

 self.miny := shape.miny;

 self.maxx := shape.maxx;

 self.maxy := shape.maxy;



TEXT --------------------------------------------------------------------------------



 if(shape.minz IS NULL) then

 self.minz := NULL;

 else

 self.minz := shape.minz;

 end if;



 if(shape.maxz IS NULL) then

 self.maxz := NULL;

 else

 self.maxz := shape.maxz;



TEXT --------------------------------------------------------------------------------

 end if;



 if(shape.minm IS NULL) then

 self.minm := NULL;

 else

 self.minm := shape.minm;

 end if;



 if(shape.maxm IS NULL) then

 self.maxm := NULL;

 else



TEXT --------------------------------------------------------------------------------

 self.maxm := shape.maxm;

 end if;



 end if;



 self.area := 0;

 self.len := shape.len;

 self.srid := srid;

 self.points := shape.points;

 Return;

 End;



TEXT --------------------------------------------------------------------------------



static Function get_release Return number IS c_type_release Constant pls_integer := 1007;



 Begin

 Return c_type_release;

 End get_release;

End;

SQL> select text from user_source where name='ST_GEOMFROMTEXT' and type='TYPE BODY';



TEXT --------------------------------------------------------------------------------

Type Body st_geomfromtext AS constructor Function st_geomfromtext(geom_str clob,srid number)

 Return self AS result

 IS

 temp varchar2(1);

 tempraw raw(1);

 entity number;

 geom_type number;

 name varchar2(32);

 spref_r SDE.spx_util.spatial_ref_record_t;



TEXT --------------------------------------------------------------------------------

 shape SDE.st_geom_util.shape_r;

 is_empty boolean := False;

 rc number;

 buffer clob;



 Begin



 geom_type := SDE.st_geom_util.unspecified_type;

 buffer := geom_str;

 SDE.st_geom_util.get_type(buffer,entity,geom_type,is_empty,SDE.st_geom_util.s

t_geometry_type);



TEXT --------------------------------------------------------------------------------





 If entity = SDE.st_geom_util.sg_illegal_shape THEN

 raise_application_error (SDE.st_type_util.st_geometry_invalid_type,'Invalid

 ST_GEOMETRY type.');



 End If;



 SDE.st_geom_util.get_name(entity,name);



 If name != 'POINT' AND name != 'LINESTRING' AND name != 'POLYGON' AND



TEXT --------------------------------------------------------------------------------

 name != 'MULTIPOINT' AND name != 'MULTILINESTRING' AND name != 'MULTIPOLYG

ON' THEN



 raise_application_error (SDE.st_type_util.st_geometry_invalid_type,'ST_GEOM

ETRY type must be a valid subtype.');  End If;



 spref_r.srid := srid;

 rc := SDE.st_spref_util.select_spref(spref_r);

 If rc <> SDE.st_type_user.se_success THEN



TEXT --------------------------------------------------------------------------------

 raise_application_error (SDE.st_type_util.spx_no_srid,'Parameter ST_SRID '||

spref_r.srid||  ' does not exist in ST_SPATIAL_REFERENCES table.');





 End If;



 shape.points := empty_blob();

 shape.numpts := 0;

 shape.entity := 0;



TEXT --------------------------------------------------------------------------------

 shape.minx := 0;

 shape.miny := 0;

 shape.maxx := 0;

 shape.maxy := 0;

 shape.area := 0;

 shape.len := 0;

 shape.minz := NULL;

 shape.maxz := NULL;

 shape.minm := NULL;

 shape.maxm := NULL;





TEXT --------------------------------------------------------------------------------

 -- Initialize POINTS blob.

 temp := lpad('a', 1, 'a');

 tempraw := utl_raw.cast_to_raw (temp);

 shape.points := tempraw;



 If is_empty = False THEN

 SDE.st_geometry_shapelib_pkg.geometryfromtext (buffer,spref_r.srid,spref_r.x_

offset,spref_r.y_offset,spref_r.xyunits,  spref_r.z_offset,spref_r.z_sca

le,spref_r.m_offset,spref_r.m_scale,



TEXT --------------------------------------------------------------------------------



 spref_r.D

ape.minx,shape.miny,



 shape.ma

hape.maxm,shape.area,shape.len,



 shape.po



 ELSE

 shape.numpts := 0;



TEXT --------------------------------------------------------------------------------

 If geom_type > SDE.st_geom_util.unspecified_type Then

 shape.entity := geom_type;

 else

 shape.entity := 0;

 end if;

 shape.minx := 0;

 shape.miny := 0;

 shape.maxx := 0;

 shape.maxy := 0;

 shape.minz := NULL;

 shape.maxz := NULL;



TEXT --------------------------------------------------------------------------------

 shape.minm := NULL;

 shape.maxm := NULL;

 shape.area := 0;

 shape.len := 0;

 shape.points := empty_blob();

 shape.srid := srid;

 End If;



 if(shape.numpts IS NULL and shape.entity = 0) then

 self.entity := shape.entity;

 self.numpts := 0;



TEXT --------------------------------------------------------------------------------

 self.minx := 0;

 self.maxx := 0;

 self.miny := 0;

 self.maxy := 0;

 self.minz := NULL;

 self.maxz := NULL;

 self.minm := NULL;

 self.maxm := NULL;

 self.srid := srid;

 else

 self.entity := shape.entity;



TEXT --------------------------------------------------------------------------------

 self.numpts := shape.numpts;

 self.minx := shape.minx;

 self.miny := shape.miny;

 self.maxx := shape.maxx;

 self.maxy := shape.maxy;



 if(shape.minz IS NULL) then

 self.minz := NULL;

 else

 self.minz := shape.minz;

 end if;



TEXT --------------------------------------------------------------------------------



 if(shape.maxz IS NULL) then

 self.maxz := NULL;

 else

 self.maxz := shape.maxz;

 end if;



 if(shape.minm IS NULL) then

 self.minm := NULL;

 else

 self.minm := shape.minm;



TEXT --------------------------------------------------------------------------------

 end if;



 if(shape.maxm IS NULL) then

 self.maxm := NULL;

 else

 self.maxm := shape.maxm;

 end if;



 end if;



 self.area := shape.area;



TEXT --------------------------------------------------------------------------------

 self.len := shape.len;

 self.srid := srid;

 self.points := shape.points;

 Return;

 End;



 static Function get_release

 Return number

 IS

 c_type_release Constant pls_integer := 1007;





TEXT --------------------------------------------------------------------------------

 Begin

 Return c_type_release;

 End get_release;

End;

CREATE OR REPLACE Type Body st_geometry AS



constructor Function st_geometry (geom_str clob, srid number)

  Return self AS result

IS

   temp            varchar2(1);

   tempraw         raw(1);

   entity          number;

   geom_type       number;

   name            varchar2(32);

   spref_r         SDE.st_spref_util.spatial_ref_record_t;

   shape           SDE.st_geom_util.shape_r;

   is_empty        boolean := False;

   rc              number;

   buffer          clob;

Begin



   geom_type := SDE.st_geom_util.unspecified_type;

   buffer := geom_str;

   SDE.st_geom_util.get_type(buffer,entity,geom_type,is_empty,SDE.st_geom_util.st_geometry_type);



   If entity = SDE.st_geom_util.sg_illegal_shape THEN

     raise_application_error (SDE.st_type_util.st_geometry_invalid_type,'ST_GEOMETRY type must be a geometry type.');

   End If;



   SDE.st_geom_util.get_name(entity,name);



   spref_r.srid := srid;

   rc := SDE.st_spref_util.select_spref(spref_r);

   If rc != SDE.st_type_user.se_success THEN

          raise_application_error (SDE.st_type_util.st_no_srid,'SRID '||spref_r.srid||

                                   ' does not exist in ST_SPATIAL_REFERENCES table.');

   End If;



   shape.points := empty_blob();

   shape.numpts := 0;

   shape.entity := 0;

   shape.minx   := 0;

   shape.miny   := 0;

   shape.maxx   := 0;

   shape.maxy   := 0;

   shape.area   := 0;

   shape.len    := 0;

   shape.minz   := NULL;

   shape.maxz   := NULL;

   shape.minm   := NULL;

   shape.maxm   := NULL;



   temp := lpad('a', 1, 'a');

   tempraw := utl_raw.cast_to_raw (temp);

   shape.points := tempraw;



   If is_empty = False THEN

     geom_type := SDE.st_geom_util.unspecified_type;

     SDE.st_geometry_shapelib_pkg.geometryfromtext(buffer,spref_r.srid,spref_r.x_offset,spref_r.y_offset,spref_r.xyunits,

                                                   spref_r.z_offset,spref_r.z_scale,spref_r.m_offset,spref_r.m_scale,

                                                   spref_r.Definition,geom_type,shape.numpts,shape.entity,shape.minx,shape.miny,

                                                   shape.maxx,shape.maxy,shape.minz,shape.maxz,shape.minm,shape.maxm,

                                                   shape.area,shape.len,shape.points);

发现最终调用的是SDE.st_geometry_shapelib_pkg.geometryfromtext函数进行对象的构建。
所以效率是一样的。
文章来源：http://blog.csdn.net/liufeng1980423/article/details/71158153