30 SDO_TIN_PKG Package (TINs)

This chapter contains descriptions of the triangulated irregular network (TIN) subprograms shown in Table 30-1.

Table 30-1 TIN Subprograms

Subprogram	Description
SDO_TIN_PKG.CLIP_TIN	Performs a clip operation on a TIN.
SDO_TIN_PKG.CREATE_TIN	Creates a TIN using the points specified in the `inptable` parameter.
SDO_TIN_PKG.DROP_DEPENDENCIES	Drops the dependencies between a TIN block table and a specified base table and column.
SDO_TIN_PKG.INIT	Initializes a TIN.
SDO_TIN_PKG.TO_GEOMETRY	Returns a geometry object representing all or part of a TIN.

To use the subprograms in this package, you must understand the main concepts related to three-dimensional geometries, including the use of triangulated irregular networks (TINs) to model surfaces. Section 1.11 describes support for three-dimensional geometries, Section 1.11.1 describes the use of TINs to model surfaces, and Section 2.5 describes data types related to TINs.

SDO_TIN_PKG.CLIP_TIN

Format

SDO_TIN_PKG.CLIP_TIN(

inp IN SDO_TIN,

qry IN SDO_GEOMETRY,

qry_min_res IN NUMBER,

qry_max_res IN NUMBER,

blkid IN NUMBER DEFAULT NULL

) RETURN SDO_TIN_BLK_TYPE;

Description

Performs a clip operation on a TIN.

Parameters

inp: TIN on which to perform the clip operation.
qry: Window from which to select objects to be returned; typically a polygon for two-dimensional geometries or a frustum for three-dimensional geometries.
qry_min_res: Minimum resolution value. Objects in qry with resolutions equal to or greater than qry_min_res and less than or equal to qry_max_res are returned by the clip operation.
qry_max_res: Maximum resolution value. Objects in qry with resolutions equal to or greater than qry_min_res and less than or equal to qry_max_res are returned by the clip operation.
blkid: Block ID number of the block to which to restrict the objects returned by the clip operation. If this parameter is null, all objects that satisfy the other parameters are returned.

Usage Notes

This function returns triangles from a TIN that are within a specified query window and that satisfy any other requirements specified by the parameters. A common use of this function is to perform queries on TINs. You can maximize the performance of a TIN query by minimizing the number of objects that the function needs to consider for the operation.

The SDO_TIN and SDO_TIN_BLK_TYPE data types are described in Section 2.5.

Section 1.11.1 describes how to use TINs to model surfaces.

Examples

The following example performs a clip operation on a TIN. It is taken from the sdo_tin.sql example program, which is under $ORACLE_HOME/md/demo/examples/TIN/plsql/ if you installed the files from the Oracle Database Examples media (see Oracle Database Examples Installation Guide).

. . .
declare
  inp  sdo_tin;
begin
  select tin INTO inp  from base where rownum=1;
  insert into restst
  select * from
    table(sdo_tin_pkg.clip_tin
           (
            inp,  -- Input TIN object
            sdo_geometry(2003, null, null,
              mdsys.sdo_elem_info_array(1, 1003, 3),
              mdsys.sdo_ordinate_array(-74.1, -73.9, 39.99999,40.00001)), -- Query
            null, null));
end;
. . .

SDO_TIN_PKG.CREATE_TIN

Format

SDO_TIN_PKG.CREATE_TIN(

inp IN SDO_TIN,

inptable IN VARCHAR2,

clstPcdataTbl IN VARCHAR2 DEFAULT NULL);

Description

Creates a TIN using the points specified in the inptable parameter.

Parameters

inp

SDO_TIN object to be used. This object must have been created by the SDO_TIN_PKG.INIT function

inptable

Name of the table or view containing the input TIN data. This table or view should have the following columns:

RID (VARCHAR2(24)): Unique ID for each point
VAL_D1 (NUMBER): Ordinate in dimension 1
VAL_D2 (NUMBER): Ordinate in dimension 2
. . .
VAL_Dn (NUMBER): Ordinate in dimension n, where n is the highest-numbered dimension. n should match the tin_tot_dimensions parameter value in the call to the SDO_TIN_PKG.INIT function when the TIN was initialized.

clstPcdataTbl

Name of the table for storing the resulting point data. If you do not specify a value, this table is not created. For more information about the table, see the Usage Notes.

Usage Notes

The first few dimensions of the TIN are indexed and can later be searched using the SDO_TIN_PKG.CLIP_TIN function. The exact number of dimensions to index is determined by the dimensionality of the TIN extent in the initialized TIN object, specifically: inp.tin_extent.sdo_gtype/1000

If you specify a view name in the inptable parameter, the query SELECT ROWID FROM <view-name> must not return any errors.

If you specify a table name in the clstPcdataTbl parameter, the table must exist and have the following columns:

PTN_ID (NUMBER)
POINT_ID (NUMBER)
RID (VARCHAR2(24): Unique ID for each point
VAL_D1 (NUMBER): Ordinate in dimension 1
VAL_D2 (NUMBER): Ordinate in dimension 2
. . .
VAL_Dn (NUMBER): Ordinate in dimension n, where n is the highest-numbered dimension. n should match the tin_tot_dimensions parameter value in the call to the SDO_TIN_PKG.INIT function when the TIN was initialized.

If a value is specified for the clstPcdataTbl parameter, this function populates the table by assigning appropriate values for PTN_ID and POINT_ID and by copying the values from the inptable table or view for other attributes. This table can be created as an index organized table. It can be used in applications for searching using SQL queries on dimensions other than those reflected in the index dimensionality. (For an explanation of index dimensionality and total dimensionality, see the explanation of the tin_tot_dimensions parameter of the SDO_TIN_PKG.INIT function.)

The SDO_TIN data type is described in Section 2.5.

Section 1.11.1 describes how to use TINs to model surfaces.

Examples

The following example creates a TIN. It is taken from the sdo_tin.sql example program, which is under $ORACLE_HOME/md/demo/examples/TIN/plsql/ if you installed the files from the Oracle Database Examples media (see Oracle Database Examples Installation Guide).

. . .
-- Create the blocks for the TIN.
sdo_tin_pkg.create_tin(
  tin,       -- Initialized TIN object
  'INPTAB', -- Name of input table to ingest into the pointcloud
  'RES'     -- Name of output table that stores the points (with ptn_id,pt_id)
);
/
. . .

SDO_TIN_PKG.DROP_DEPENDENCIES

Format

SDO_TIN_PKG.DROP_DEPENDENCIES(

basetable IN VARCHAR2,

col IN VARCHAR2);

Description

Drops the dependencies between a TIN block table and a specified base table and column.

Parameters

basetable: Name of a base table that was specified (in the basetable parameter of the SDO_TIN_PKG.INIT function) when the TIN was initialized.
col: Name of a column in base table that was specified in the basecol parameter of the SDO_TIN_PKG.INIT function.

Usage Notes

This procedure truncates the TIN block table and removes the association between the block table and the base table and column combination.

After you execute this procedure, you can drop the TIN block table or associate the table with another base table and column combination. For more information, see the Usage Notes for the SDO_TIN_PKG.INIT function.

Examples

The following example drops the dependencies between a TIN block table and a base table and column named BASE and TIN, respectively.

. . .
declare
begin
  mdsys.sdo_tin_pkg.drop_dependencies('BASE', 'TIN');
end;
/

SDO_TIN_PKG.INIT

Format

SDO_TIN_PKG.INIT(

basetable IN VARCHAR2,

basecol IN VARCHAR2,

blktable IN VARCHAR2,

ptn_params IN VARCHAR2,

tin_extent IN VARCHAR2L,

tin_tol IN NUMBER DEFAULT 0.000000000000005,

tin_tot_dimensions IN NUMBER DEFAULT 2,

tin_domain IN SDO_ORGSCL_TYPE DEFAULT NULL,

tin_break_lines IN SDO_GEOMETRY DEFAULT NULL,

tin_stop_lines IN SDO_GEOMETRY DEFAULT NULL,

tin_void_rgns IN SDO_GEOMETRY DEFAULT NULL,

tin_val_attr_tables IN SDO_STRING_ARRAY DEFAULT NULL,

tin_other_attrs IN XMLTYPE DEFAULT NULL,

) RETURN SDO_TIN;

Description

Initializes a TIN by creating an SDO_TIN object.

Parameters

basetable

Name of the base table containing a column of type SDO_TIN.

basecol

Name of the column of type SDO_TIN in the base table.

blktable

Name of the TIN block table, which is used for storing the blocks of the TIN. This table must exist, and must have been created by a statement in the following form: CREATE TABLE <table-name> AS select * from mdsys.sdo_tin_blk_table;

Each TIN block table can only be associated with only one basetable and basecol combination.

ptn_params

Parameters for partitioning the TIN, specified as a quoted string with keywords delimited by commas. For example: 'blk_capacity=1000,work_tablespace=my_work_ts'. If this parameter is null, the TIN is not partitioned. The following keywords are permitted:

blk_capacity=n, where n is the maximum number of rows in each partition. The default value is 5000. If specified, must be a number greater than or equal to 50.
work_tablespace=x, where x is the name of the tablespace in which to create temporary tables during the partitioning operations.

tin_extent

SDO_GEOMETRY object representing the spatial extent of the TIN (the minimum bounding object enclosing all objects in the TIN. This parameter must not be null.

For geodetic data, this geometry must have two dimensions; otherwise, it can have up to four dimensions. The dimensionality of this geometry is used as the minimum value permitted for the tin_tot_dimensions parameter, as explained in the description of that parameter.

tin_tol

Tolerance value for objects in the TIN. (For information about spatial tolerance, see Section 1.5.5.) If this parameter is null, the default value is 0.0000000000005.

tin_tot_dimensions

A number specifying the total dimensionality of the TIN object. For each point in the TIN blocks, tin_tot_dimensions ordinates (values) are stored.

The total dimensionality must be greater than or equal to the index dimensionality, which is the number of dimensions in the tin_extent geometry. Specifying total dimensionality greater than index dimensionality enables necessary nonspatial attributes to be retrieved in the same fetch operation with spatial data. The maximum total dimensionality value is 8. The default value for this parameter is 2.

tin_domain

(Not currently used.)

tin_break_lines

(Not currently used.)

tin_stop_lines

Line string or multiline string SDO_GEOMETRY object representing the stop line or lines in the TIN. If this parameter is null, the TIN contains no stop lines. Stop lines typically indicate places where the elevation lines are not continuous, such as the slope from the top to the bottom of a cliff. Such regions are to be excluded from the TIN.

tin_void_rgns

(Not currently used.)

tin_val_attr_tables

SDO_STRING_ARRAY object specifying the names of any value attribute tables for the TIN. If this parameter is null, the TIN has no associated value attribute tables. Type SDO_STRING_ARRAY is defined as VARRAY(1048576) OF VARCHAR2(32).

tin_other_attrs

XMLTYPE object specifying any other attributes of the TIN. If this parameter is null, the TIN has no other attributes.

Usage Notes

After you use this function to create an SDO_TIN object, you can create a TIN by specifying this object as input to the SDO_TIN_PKG.CREATE_TIN procedure.

The SDO_TIN data type is described in Section 2.5.

Section 1.11.1 describes how to use TINs to model surfaces.

Examples

The following example initializes a TIN by creating an SDO_TIN object. It is taken from the sdo_tin.sql example program, which is under $ORACLE_HOME/md/demo/examples/TIN/plsql/ if you installed the files from the Oracle Database Examples media (see Oracle Database Examples Installation Guide).

declare
  tin sdo_tin;
begin
  -- Initialize the TIN object. 
  tin := sdo_tin_pkg.init(
          'BASE', -- Table that has the SDO_TIN column defined
          'TIN',   -- Column name of the SDO_TIN object 
          'BLKTAB', -- Table to store blocks of the TIN
           'blk_capacity=1000', -- max # of points per block 
           mdsys.sdo_geometry(2003, null, null,
              mdsys.sdo_elem_info_array(1,1003,3),
              mdsys.sdo_ordinate_array(-180, -90, 180, 90)),  -- Extent 
              0.0000000005, -- Tolerance for TIN
              3, -- Total number of dimensions
              null);
. . .

SDO_TIN_PKG.TO_GEOMETRY

Format

SDO_TIN_PKG.TO_GEOMETRY(

pts IN BLOB,

trs IN BLOB,

num_pts IN NUMBER,

num_trs IN NUMBER,

tin_tot_dim IN NUMBER,

srid IN NUMBER DEFAULT NULL,

blk_domain IN SDO_ORGSCL_TYPE DEFAULT NULL

) RETURN SDO_GEOMETRY;

Description

Returns a geometry object representing all or part of a TIN.

Parameters

pts: BLOB containing points.
trs: BLOB containing triangles.
num_pts: Maximum number of points to be included in the resulting geometry.
num_pts: Maximum number of triangles to be included in the resulting geometry.
tin_tot_dim: Number of spatial dimensions defined for the data.
srid: Spatial reference (coordinate system) ID associated with the data. If this parameter is null, no SRID value is associated with the data.
blk_domain: (Not currently used.)

Usage Notes

This function returns a single collection SDO_GEOMETRY object that represents all point geometries in the pts parameter and all triangle geometries in the trs parameter. For example, the points and triangles could reflect the result of a clip operation or the contents of an entire block.

Section 1.11.1 describes how to use TINs to model surfaces.

Examples

The following example returns a multipoint collection geometry object representing a TIN. It is taken from the sdo_tin.sql example program, which is under $ORACLE_HOME/md/demo/examples/TIN/plsql/ if you installed the files from the Oracle Database Examples media (see Oracle Database Examples Installation Guide).

. . .
-- Return points in blk_id of the TIN as a multipoint collection. 
select sdo_tin_pkg.to_geometry(
                    a.points,   -- point LOB
                    a.triangles,   -- point LOB
                    a.num_points, -- # of points in the LOB
                    a.num_triangles, -- # of points in the LOB
                    2,  -- index dimensionality (gtype dim in extent in INIT)
                    3,  -- total dimensionality
                    null -- SRID
                    ) from blktab a where blk_id=0;
. . .