scan0077 - SDO_G EOMETRY Object Type'VAL_RESULTS 2 SELECT...

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Unformatted text preview: SDO_G EOMETRY Object Type 'VAL_RESULTS', 2); SELECT * from val_results; 2.2 SDO_GEOMETRY Object Type With Spatial, the geometric description of a spatial object is stored in a single row, in a single column of object type SDO_GEOMETRY in a user—defined table. Any table that has a column of type SDO_GEOMETRY must have another column, or set of columns, that defines a unique primary key for that table. Tables of this sort are sometimes referred to as spatial tables or spatial geometry tables, Oracle Spatial defines the object type SDO_GEOMETRY as: CREATE TYPE sdo_geometry AS OBJECT ( SDO_GTYPE NUMBER, SDO_SRID NUMBER, SDO_POINT SDO_POINT_TYPE, SDoiELEM_INFO SDO_ELEM_INFO_ARRAY, SDO_ORDINATES SDO_ORDINATE_ARRAY); Oracle Spatial also defines the SDO_POINT_TYPE, SDO_ELEM_INFO_ARRAY, and SDO_ORDINATE_ARRAY types, which are used in the SDO_GEOMETRY type definition, as follows: CREATE TYPE sdo_poin:_type as OBJECT ( X NUMBER, Y NUMBER, 2 NUMBER): CREATE TYPE sdo_elem_info_array AS VARRAY (1048576) of NUMBER; CREATE TYPE sdo_ordinate_array AS VARRAY (1048576) of NUMBER; Because the maximum SDO_ORDINATE_ARRAY size is 1,048,576 numbers, the maximum number of vertices in an SDO_GEOMETRY object depends on the number of dimensions per vertex: 524,288 for two dimensions, 349,525 for three dimensions, and 262,144 for four dimensions. The sections that follow describe the semantics of each SDO_GEOMETRY attribute, and then describe some usage considerations (Section 2.2.6). The SDO_GEOMETRY object type has methods that provide convenient access to some of the attributes. These methods are described in Section 2.3. Some Spatial data types are described in locations other than this section: I Section 5.2 describes data types for geocoding. - Oracle Spatial GeoRaster describes data types for Oracle Spatial GeoRaster. - Oracle Spatial Topology and Network Data Models describes data types for the Oracle Spatial topology data model. 2.2.1 SDO_GTYPE The SDO_GTYPE attribute indicates the type of the geometry. Valid geometry types correspond to those specified in the Geometry Object Model for the 0615 Simple Features for SQL specification (with the exception of Surfaces). The numeric values differ from those given in the OGIS specification, but there is a direct correspondence between the names and semantics where applicable. The SDO_GTYPE value is 4 digits in the format dltt, where: I a' identifies the number of dimensions (2, 3, or 4) Spatial Data Types and Metadala 2-5 ...
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