[postgis-devel] Oracle SDO_GEOMETRY vs PostGIS WKT

[Andrea Peri]

>Do you have any answer to Jorges initial question why the Oracle geometry representation (sdo_geometry) seems so complicated if it is not about topology?

It not seem complicated it is complicated :)

1)
almost in the 10g version, oracle don't support EPSG definition of SRS,
but use another coding.

2)
define a new table is easy:

create table table-1 ( id number, poi_name varchar2(32), location sdo_geometry);

but when need to insert in it is a bit more complex then in postgis.

insert into table-1 values
(   1,
    'aaaa',
    sdo_geometry(
        2001, // sdo_gtype attribute: "2" in 2001 mean 2-dimensionality
        NULL,  // this was the SRID (SRS) code
        sdo_point_type (
           xx, // first coordinate,
           yy, // second coordinate,
           NULL, // third coordinate
        ),
        NULL,
        NULL
    ),
);

as you can see insert a point is more complex then a simple WKT use
from postgis.

Too complex again if you want store a Linestring or a polygon beacause
must use a structure like an array.

sdo_geometry (
   2001,  // again use 2001 because you polygon or linestirng is 2-dimensional
   8307 , // srid code
   NULL,  // sdo_pont attribute set to null
   sdo_elem_info_array (
     ...
   ),
   sdo_ordinate_array (
   ....
   )
)

etc....


-----------------
Andrea Peri
. . . . . . . . .
qwerty àèìòù
-----------------
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