31 SDO_SAM Package (Spatial Analysis and Mining)
The MDSYS.SDO_SAM package contains subprograms for spatial analysis and data mining.
To use the subprograms in this chapter, you must understand the conceptual information about spatial analysis and data mining in Spatial Analysis and Mining.
Note:
SDO_SAM subprograms are supported for two-dimensional geometries only. They are not supported for three-dimensional geometries.
The rest of this chapter provides reference information on the spatial analysis and mining subprograms, listed in alphabetical order.
- SDO_SAM.AGGREGATES_FOR_GEOMETRY
- SDO_SAM.AGGREGATES_FOR_LAYER
- SDO_SAM.BIN_GEOMETRY
- SDO_SAM.BIN_LAYER
- SDO_SAM.COLOCATED_REFERENCE_FEATURES
- SDO_SAM.SIMPLIFY_GEOMETRY
- SDO_SAM.SIMPLIFY_LAYER
- SDO_SAM.SPATIAL_CLUSTERS
- SDO_SAM.TILED_AGGREGATES
- SDO_SAM.TILED_BINS
Parent topic: Reference Information
31.1 SDO_SAM.AGGREGATES_FOR_GEOMETRY
Format
SDO_SAM.AGGREGATES_FOR_GEOMETRY( theme_name IN VARCHAR2, theme_colname IN VARCHAR2, aggr_type_string IN VARCHAR2, aggr_col_string IN VARCHAR2, geom IN SDO_GEOMETRY, dst_spec IN VARCHAR2 DEFAULT NULL ) RETURN NUMBER;
Description
Computes the thematic aggregate for a geometry.
Parameters
- theme_name
-
Name of the theme table.
- theme_colname
-
Name of the geometry column in
theme_name
. - aggr_type_string
-
Any Oracle SQL aggregate function that accepts one or more numeric values and computes a numeric value, such as
SUM
,MIN
,MAX
, orAVG
. - aggr_col_string
-
Name of a column in
theme_name
on which to compute aggregate values, as explained in the Usage Notes. An example might be a POPULATION column. - geom
-
Geometry object.
- dst_spec
-
A quoted string specifying either a distance buffer or a number of nearest neighbor geometries to consider. See the Usage Notes for an explanation of the format and meaning.
Usage Notes
For a specific geometry, this function identifies the geometries in the theme_name
table, finds their intersection ratio, multiplies the specified aggregate using this intersection ratio, and aggregates it for the geometry. Specifically, for all rows of the theme_name
table that intersect with the specified geometry, it returns the value from the following function:
aggr_type_string(aggr_col_string * proportional_area_of_intersection(geometry, theme_name.theme_colname))
The theme_colname
column must have a spatial index defined on it. For best performance, insert simplified geometries into this column.
The dst_spec
parameter, if specified, is a quoted string that must contain either of the following:
-
The
distance
keyword and optionally theunit
keyword (unit of measurement associated with the distance value), to specify a buffer around the geometry. For example,'distance=2 unit=km'
specifies a 2-kilometer buffer around the input geometry. Ifdst_spec
is not specified, no buffer is used.If the
unit
keyword is specified, the value must be an SDO_UNIT value from the MDSYS.SDO_DIST_UNITS table (for example,'unit=km'
). If theunit
keyword is not specified, the unit of measurement associated with the geometry is used. See Unit of Measurement Support for more information about unit of measurement specification. -
The
sdo_num_res
keyword, to specify the number of nearest-neighbor geometries to consider, without considering proportional coverage. For example,'sdo_num_res=5'
could be used in a query that asks for the populations of the five cities that are nearest to a specified point.
Examples
The following example computes the thematic aggregate for an area with a 3-mile radius around a specified point geometry. In this case, the total population of the area is computed based on the proportion of the circle's area within different counties, assuming uniform distribution of population within the counties.
SELECT sdo_sam.aggregates_for_geometry( 'GEOD_COUNTIES', 'GEOM', 'sum', 'totpop', SDO_GEOMETRY(2001, 8307, SDO_POINT_TYPE(-73.943849, 40.6698,NULL), NULL, NULL), 'distance=3 unit=mile') FROM DUAL a ;
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)
31.2 SDO_SAM.AGGREGATES_FOR_LAYER
Format
SDO_SAM.AGGREGATES_FOR_LAYER( theme_name IN VARCHAR2, theme_colname IN VARCHAR2, aggr_type_string IN VARCHAR2, aggr_col_string IN VARCHAR2, tablename IN VARCHAR2, colname IN VARCHAR2, dst_spec IN VARCHAR2 DEFAULT NULL ) RETURN SDO_REGAGGRSET;
Description
Computes thematic aggregates for a layer of geometries.
Parameters
- theme_name
-
Name of the theme table.
- theme_colname
-
Name of the geometry column in
theme_name
. - aggr_type_string
-
Any Oracle SQL aggregate function that accepts one or more numeric values and computes a numeric value, such as
SUM
,MIN
,MAX
, orAVG
. - aggr_col_string
-
Name of a column in
theme_name
on which to compute aggregate values, as explained in the Usage Notes. An example might be a POPULATION column. - tablename
-
Name of the data mining table.
- colname
-
Name of the column in
tablename
that holds the geometries. - dst_spec
-
A quoted string specifying either a distance buffer or a number of nearest neighbor geometries to consider. See the Usage Notes for the SDO_SAM.AGGREGATES_FOR_GEOMETRY function in this chapter for an explanation of the format and meaning.
Usage Notes
For each geometry in tablename
, this function identifies the geometries in the theme_name
table, finds their intersection ratio, multiplies the specified aggregate using this intersection ratio, and aggregates it for each geometry in tablename
. Specifically, for all rows of the theme_name
table, it returns the value from the following function:
aggr_type_string(aggr_col_string * proportional_area_of_intersection(geometry, theme_name.theme_colname))
This function returns an object of type SDO_REGAGGRSET. The SDO_REGAGGRSET object type is defined as:
TABLE OF SDO_REGAGGR
The SDO_REGAGGR object type is defined as:
Name Null? Type ----------------------------------------- -------- ---------------------------- REGION_ID VARCHAR2(24) GEOMETRY MDSYS.SDO_GEOMETRY AGGREGATE_VALUE NUMBER
The theme_colname
column must have a spatial index defined on it. For best performance, insert simplified geometries into this column.
Examples
The following example computes the thematic aggregates for all geometries in a table named TEST_TAB for an area with a 3-mile radius around a specified point geometry. In this case, the total population of each area is computed based on the proportion of the circle's area within different counties, assuming uniform distribution of population within the counties.
SELECT a.aggregate_value FROM TABLE(sdo_sam.aggregates_for_layer( 'GEOD_COUNTIES', 'GEOM', 'SUM', TOTPOP', TEST_TAB', 'GEOM' 'distance=3 unit=mile')) a;
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)
31.3 SDO_SAM.BIN_GEOMETRY
Format
SDO_SAM.BIN_GEOMETRY( geom IN SDO_GEOMETRY, tol IN SDO_DIM_ARRAY, bin_tablename IN VARCHAR2, bin_colname IN VARCHAR2 ) RETURN NUMBER;
or
SDO_SAM.BIN_GEOMETRY( geom IN SDO_GEOMETRY, dim IN SDO_DIM_ARRAY, bin_tablename IN VARCHAR2, bin_colname IN VARCHAR2 ) RETURN NUMBER;
Description
Computes the most-intersecting tile for a geometry.
Parameters
- geom
-
Geometry for which to compute the bin.
- tol
-
Tolerance value (see Tolerance).
- dim
-
Dimensional array for the table that holds the geometries for the bins.
- bin_tablename
-
Name of the table that holds the geometries for the bins.
- bin_colname
-
Column in
bin_tablename
that holds the geometries for the bins.
Usage Notes
This function returns the bin that intersects most with the specified geometry. If multiple bins intersect to the same extent with the specified geometry, the bin with the smallest area is returned.
To perform this operation on all rows in the data mining table, using the specified bin_tablename
, you can use the SDO_SAM.BIN_LAYER procedure.
Examples
The following example computes the bin for a specified geometry.
SELECT sdo_sam.bin_geometry(a.geometry, 0.0000005, 'BINTBL', 'GEOMETRY') FROM poly_4pt a, user_sdo_geom_metadata b WHERE b.table_name='POLY_4PT' AND a.gid=1; SDO_SAM.BIN_GEOMETRY(A.GEOMETRY,0.0000005,'BINTBL','GEOMETRY') -------------------------------------------------------------- 43 1 row selected.
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)
31.4 SDO_SAM.BIN_LAYER
Format
SDO_SAM.BIN_LAYER( tablename IN VARCHAR2, colname IN VARCHAR2, bin_tablename IN VARCHAR2, bin_colname IN VARCHAR2, bin_id_colname IN VARCHAR2, commit_interval IN NUMBER DEFAULT 20);
Description
Assigns each location (and the corresponding row) in a data mining table to a spatial bin.
Parameters
- tablename
-
Name of the data mining table.
- colname
-
Name of the column in
table_name
that holds the location coordinates. - bin_tablename
-
Name of the table that contains information (precomputed for the entire two-dimensional space) about the spatial bins.
- bin_colname
-
Column in
bin_tablename
that holds the geometries for the bins. - bin_id_colname
-
Name of the column in the data mining table that holds the bin ID value of each geometry added to a bin. (Each affected row in the data mining table is updated with the ID value of the bin geometry in
bin_tablename
.) - commit_interval
-
Number of bin insert operations to perform before Spatial performs an internal commit operation. If
commit_interval
is not specified, a commit is performed after every 20 insert operations.
Usage Notes
This procedure computes the most-intersecting tile for each geometry in a specified layer using the bins in bin_tablename
. The bin ID value for each geometry is added in bin_id_colname
.
Using this procedure achieves the same result as using the SDO_SAM.BIN_GEOMETRY function on each row in the data mining table, using the specified bin_tablename
.
Examples
The following example assigns each GEOMETRY column location and corresponding row in the POLY_4PT_TEMP data mining table to a spatial bin, and performs an internal commit operation after each bin table insertion.
CALL SDO_SAM.BIN_LAYER('POLY_4PT_TEMP', 'GEOMETRY', 'BINTBL', 'GEOMETRY', 'BIN_ID', 1);
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)
31.5 SDO_SAM.COLOCATED_REFERENCE_FEATURES
Format
SDO_SAM.COLOCATED_REFERENCE_FEATURES( theme_tablename IN VARCHAR2, theme_colname IN VARCHAR2, theme_predicate IN VARCHAR2, tablename IN VARCHAR2, colname IN VARCHAR2, ref_predicate IN VARCHAR2, dst_spec IN VARCHAR2, result_tablename IN VARCHAR2, commit_interval IN NUMBER DEFAULT 100);
Description
Performs a partial predicate-based join of tables, and materializes the join results into a table.
Parameters
- theme_tablename
-
Name of the table with which to join
tablename
. - theme_colname
-
Name of the geometry column in
theme_tablename
. - theme_predicate
-
Qualifying WHERE clause predicate to be applied to
theme_tablename
. - tablename
-
Name of the data mining table.
- colname
-
Name of the column in
tablename
that holds the location coordinates. - ref_predicate
-
Qualifying WHERE clause predicate to be applied to
tablename
. Must a null or non-null value: if null, no predicate is applied; if non-null, it must be a single table predicate, such as'country_code=10'.
- dst_spec
-
A quoted string containing a distance value and optionally a unit value for a buffer around the geometries. See the Usage Notes for an explanation of the format and meaning.
- result_tablename
-
The table in which materialized join results are stored. This table must exist and must have the following definition:
(tid NUMBER, rid1 VARCHAR2(24), rid2 VARCHAR2(24))
- commit_interval
-
Number of internal join operations to perform before Spatial performs an internal commit operation. If
commit_interval
is not specified, a commit is performed after every 100 internal join operations.
Usage Notes
This procedure materializes each pair of rowids returned from a predicate-based join operation, and stores them in the rid1, rid2
columns of result_tablename
. The tid
is a unique generated "interaction" number corresponding to each rid1
value.
The dst_spec
parameter, if specified, is a quoted string containing the distance
keyword and optionally the unit
keyword (unit of measurement associated with the distance value), to specify a buffer around the geometry. For example, 'distance=2 unit=km'
specifies a 2-kilometer buffer around the input geometry. If dst_spec
is not specified, no buffer is used.
If the unit
keyword is specified, the value must be an SDO_UNIT value from the MDSYS.SDO_DIST_UNITS table (for example, 'unit=KM'
). If the unit
keyword is not specified, the unit of measurement associated with the geometry is used. See Unit of Measurement Support for more information about unit of measurement specification.
Examples
The following example identifies cities with a 1990 population (POP90 column value) greater than 120,000 that are located within 20 kilometers of interstate highways (GEOM column in the GEOD_INTERSTATES table). It stores the results in a table named COLOCATION_TABLE, and performs an internal commit operation after each 20 internal operations.
EXECUTE SDO_SAM.COLOCATED_REFERENCE_FEATURES( 'geod_cities', 'location', 'pop90 > 120000', 'geod_interstates', 'geom', null, 'distance=20 unit=km', 'colocation_table', 20);
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)
31.6 SDO_SAM.SIMPLIFY_GEOMETRY
Format
SDO_SAM.SIMPLIFY_GEOMETRY( geom IN SDO_GEOMETRY, dim IN SDO_DIM_ARRAY, pct_area_change_limit IN NUMBER DEFAULT 2 ) RETURN SDO_GEOMETRY;
or
SDO_SAM.SIMPLIFY_GEOMETRY( geom IN SDO_GEOMETRY, tol IN NUMBER, pct_area_change_limit IN NUMBER DEFAULT 2 ) RETURN SDO_GEOMETRY;
Description
Simplifies a geometry.
Parameters
- geom
-
Geometry to be simplified.
- dim
-
Dimensional array for the geometry to be simplified.
- tol
-
Tolerance value (see Tolerance).
- pct_area_change_limit
-
The percentage of area changed to be used for each simplification iteration, as explained in the Usage Notes.
Usage Notes
This function reduces the number of vertices in a geometry by internally applying the SDO_UTIL.SIMPLIFY function (documented in SDO_UTIL Package (Utility)) with an appropriate threshold value.
Reducing the number of vertices may result in a change in the area of the geometry. The pct_area_change_limit
parameter specifies how much area change can be tolerated while simplifying the geometry. It is usually a number from 1 to 100. The default value is 2; that is, the area of the geometry can either increase or decrease by at most two percent compared to the original geometry as a result of the geometry simplification.
Examples
The following example simplifies the geometries in the GEOMETRY column of the POLY_4PT_TEMP table.
SELECT sdo_sam.simplify_geometry(a.geometry, 0.00000005) FROM poly_4pt_temp a, user_sdo_geom_metadata b WHERE b.table_name='POLY_4PT_TEMP' ; SDO_SAM.SIMPLIFY_GEOMETRY(A.GEOMETRY,0.00000005)(ORIG_AREA, CUR_AREA, ORIG_LEN, -------------------------------------------------------------------------------- SDO_SMPL_GEOMETRY(28108.5905, 28108.5905, 758.440118, 758.440118, SDO_GEOMETRY(2 003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 1), SDO_ORDINATE_ARRAY(-122.4215, 37.7862, -122.422, 37.7869, -122.421, 37.789, -122.42, 37.7866, -122.4215, 37.78 62))) SDO_SMPL_GEOMETRY(4105.33806, 4105.33806, 394.723053, 394.723053, SDO_GEOMETRY(2 003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 1), SDO_ORDINATE_ARRAY(-122.4019, 37.8052, -122.4027, 37.8055, -122.4031, 37.806, -122.4012, 37.8052, -122.4019, 3 7.8052))) . . . 50 rows selected.
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)
31.7 SDO_SAM.SIMPLIFY_LAYER
Format
SDO_SAM.SIMPLIFY_LAYER( theme_tablename IN VARCHAR2, theme_colname IN VARCHAR2, smpl_geom_colname IN VARCHAR2, commit_interval IN NUMBER DEFAULT 10, pct_area_change_limit IN NUMBER DEFAULT 2);
Description
Simplifies a geometry layer.
Parameters
- theme_tablename
-
Name of the table containing the geometry layer to be simplified.
- theme_colname
-
Column in
theme_tablename
of type SDO_GEOMETRY containing the geometries to be simplified. - smpl_geom_colname
-
Column in
theme_tablename
of type SDO_GEOMETRY into which the simplified geometries are to be placed by this procedure. - commit_interval
-
Number of geometries to simplify before Spatial performs an internal commit operation. If
commit_interval
is not specified, a commit is performed after every 10 simplification operations. - pct_area_change_limit
-
The percentage of area changed to be used for each simplification iteration, as explained in the Usage Notes for the SDO_SAM.SIMPLIFY_GEOMETRY function.
Usage Notes
This procedure simplifies all geometries in a layer. It is equivalent to calling the SDO_SAM.SIMPLIFY_GEOMETRY function for each geometry in the layer, except that each simplified geometry is put in a separate column in the table instead of being returned to the caller. See also the Usage Notes for the SDO_SAM.SIMPLIFY_GEOMETRY function.
Examples
The following example adds a column named SMPL_GEOM to the POLY_4PT_TEMP table, then simplifies all geometries in the GEOMETRY column of the POLY_4PT_TEMP table, placing each simplified geometry in the SMPL_GEOM column in the same row with its associated original geometry.
ALTER TABLE poly_4pt_temp ADD (smpl_geom mdsys.sdo_geometry); Table altered. EXECUTE sdo_sam.simplify_layer('POLY_4PT_TEMP', 'GEOMETRY', 'SMPL_GEOM'); PL/SQL procedure successfully completed.
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)
31.8 SDO_SAM.SPATIAL_CLUSTERS
Format
SDO_SAM.SPATIAL_CLUSTERS( tablename IN VARCHAR2, colname IN VARCHAR2, max_clusters IN NUMBER, allow_outliers IN VARCHAR2 DEFAULT 'TRUE', tablepartition IN VARCHAR2 DEFAULT NULL ) RETURN SDO_REGIONSET;
Description
Computes clusters using the existing R-tree index, and returns a set of SDO_REGION objects where the geometry column specifies the boundary of each cluster and the geometry_key
value is set to null.
Parameters
- tablename
-
Name of the data mining table.
- colname
-
Name of the column in
tablename
that holds the location coordinates. - max_clusters
-
Maximum number of clusters to obtain.
- allow_outliers
-
TRUE
(the default) causes outlying values (isolated instances) to be included in the spatial clusters;FALSE
causes outlying values not to be included in the spatial clusters. (TRUE
accommodates all data and may result in larger clusters;FALSE
may exclude some data and may result in smaller clusters.) - tablepartition
-
Name of the partition in
tablename
.
Usage Notes
The clusters are computed using the spatial R-tree index on tablename
.
Examples
The following example clusters the locations in cities into at most three clusters, and includes outlying values in the clusters.
SELECT * FROM TABLE(sdo_sam.spatial_clusters('PROJ_CITIES', 'LOCATION', 3, 'TRUE'));
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)
31.9 SDO_SAM.TILED_AGGREGATES
Format
SDO_SAM.TILED_AGGREGATES( theme_name IN VARCHAR2, theme_colname IN VARCHAR2, aggr_type_string IN VARCHAR2, aggr_col_string IN VARCHAR2, tiling_level IN NUMBER DEFAULT NULL, tiling_domain IN SDO_DIM_ARRAY DEFAULT NULL, zero_agg_tiles IN NUMBER DEFAULT 0, xdivs IN NUMBER DEFAULT NULL, ydivs IN NUMBER DEFAULT NULL ) RETURN SDO_REGAGGRSET;
Description
Tiles aggregates for a domain. For each tile, computes the intersecting geometries from the theme table; the values in the aggr_col_string
column are weighted proportionally to the area of the intersection, and aggregated according to aggr_col_string
.
Parameters
- theme_name
-
Table containing theme information (for example, demographic information).
- theme_colname
-
Name of the column in the
theme_name
table that contains geometry objects. - aggr_type_string
-
Any Oracle SQL aggregate function that accepts one or more numeric values and computes a numeric value, such as
SUM
,MIN
,MAX
, orAVG
. - aggr_col_string
-
Name of a column in the
theme_name
table on which to compute aggregate values. An example might be a POPULATION column. - tiling_level
-
Level to be used to create tiles. If you specify this parameter, the extent of each dimension is divided into 2^
tiling_level
parts, resulting in at most 4*tiling_level
tiles. (Specify either this parameter or the combination of thexdivs
andydivs
parameters.) - tiling_domain
-
Domain for the tiling level. The parameter is not required, and if you do not specify it, the extent associated with the
theme_name
table is used. - zero_agg_tiles
-
Specify 0 to exclude tiles that have a value of 0 for the computed aggregate, or specify 1 to return all tiles. The default value is 0, which ensures that only tiles with a nonzero aggregate value are returned.
- xdivs
-
The number of times that the extent in the first dimension is divided, such that the total number of parts is
xdivs
+ 1. For example, if you specify 10 forxdivs
, the extent of the first dimension is divided into 11 parts. - ydivs
-
The number of times that the extent in the second dimension is divided, such that the total number of parts is
ydivs
+ 1. For example, if you specify 10 forydivs
, the extent of the second dimension is divided into 11 parts.
Usage Notes
This function is similar to SDO_SAM.AGGREGATES_FOR_LAYER, but the results are dynamically generated using tiling information. Given a theme_name
table, the tiling domain is determined. Based on the tiling_level
value or the xdivs
and ydivs
values, the necessary tiles are generated. For each tile geometry, thematic aggregates are computed as described in the Usage Notes for SDO_SAM.AGGREGATES_FOR_LAYER.
You must specify either the tiling_level
parameter or both the xdivs
and ydivs
parameters. If you specify all three of these parameters, the tiling_level
parameter is ignored and the xdivs
and ydivs
parameters are used.
If you specify the xdivs
and ydivs
parameters, the total number of grids (tiles) returned is (xdivs+1)*(ydivs+1)
.
This function returns an object of type SDO_REGAGGRSET. The SDO_REGAGGRSET object type is defined as:
TABLE OF SDO_REGAGGR
The SDO_REGAGGR object type is defined as:
Name Null? Type ----------------------------------------- -------- ---------------------------- REGION_ID VARCHAR2(24) GEOMETRY MDSYS.SDO_GEOMETRY AGGREGATE_VALUE NUMBER
Examples
The following example computes the sum of the population rows of POLY_4PT_TEMP table intersecting with each tile. The extent of the POLY_4PT_TEMP table stored in the USER_SDO_GEOM_METADATA view is used as the domain, and a tiling level of 2 is used (that is, the domain is divided into 16 tiles).
SELECT a.geometry, a.aggregate_value from TABLE(sdo_sam.tiled_aggregates('POLY_4PT_TEMP', 'GEOMETRY', 'SUM', 'POPULATION', 2)) a; GEOMETRY(SDO_GTYPE, SDO_SRID, SDO_POINT(X, Y, Z), SDO_ELEM_INFO, SDO_ORDINATES) -------------------------------------------------------------------------------- AGGREGATE_VALUE --------------- SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(-180, -90, -90, -45)) .007150754 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(-180, -45, -90, 0)) .034831005 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(-180, 0, -90, 45)) 7.73307783 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(-90, -90, 0, -45)) .019498368 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(-90, -45, 0, 0)) .939061456 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(-90, 0, 0, 45)) 1.26691592 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(0, 0, 90, 45)) 40 7 rows selected.
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)
31.10 SDO_SAM.TILED_BINS
Format
SDO_SAM.TILED_BINS( l1 IN NUMBER, u1 IN NUMBER, l2 IN NUMBER, u2 IN NUMBER, tiling_level IN NUMBER DEFAULT NULL, srid IN NUMBER DEFAULT NULL, xdivs IN NUMBER DEFAULT NULL, ydivs IN NUMBER DEFAULT NULL ) RETURN SDO_REGIONSET;
Description
Tiles a two-dimensional space and returns geometries corresponding to those tiles.
Parameters
- l1
-
Lower bound of the extent in the first dimension.
- u1
-
Upper bound of the extent in the first dimension.
- l2
-
Lower bound of the extent in the second dimension.
- u2
-
Upper bound of the extent in the second dimension.
- tiling_level
-
Level to be used to tile the specified extent. If you specify this parameter, the extent of each dimension is divided into 2^
tiling_level
parts, resulting in at most 4*tiling_level
tiles. (Specify either this parameter or the combination of thexdivs
andydivs
parameters.) - srid
-
SRID value to be included for the coordinate system in the returned tile geometries.
- xdivs
-
The number of times that the extent in the first dimension is divided, such that the total number of parts is
xdivs
+ 1. For example, if you specify 10 forxdivs
, the extent of the first dimension is divided into 11 parts. - ydivs
-
The number of times that the extent in the second dimension is divided, such that the total number of parts is
ydivs
+ 1. For example, if you specify 10 forydivs
, the extent of the second dimension is divided into 11 parts.
Usage Notes
You must specify either the tiling_level
parameter or both the xdivs
and ydivs
parameters. If you specify all three of these parameters, the tiling_level
parameter is ignored and the xdivs
and ydivs
parameters are used.
If you specify the xdivs
and ydivs
parameters, the total number of grids (tiles) returned is (xdivs+1)*(ydivs+1)
.
This function returns an object of type SDO_REGIONSET. The SDO_REGIONSET object type is defined as:
TABLE OF SDO_REGION
The SDO_REGION object type is defined as:
Name Null? Type ----------------------------------------- -------- ---------------------------- ID NUMBER GEOMETRY MDSYS.SDO_GEOMETRY
Examples
The following example tiles the entire Earth's surface at the first tiling level, using the standard longitude and latitude coordinate system (SRID 8307). The resulting SDO_REGIONSET object contains four SDO_REGION objects, one for each tile.
SELECT * FROM TABLE(sdo_sam.tiled_bins(-180, 180, -90, 90, 1, 8307)) ORDER BY id; ID ---------- GEOMETRY(SDO_GTYPE, SDO_SRID, SDO_POINT(X, Y, Z), SDO_ELEM_INFO, SDO_ORDINATES) -------------------------------------------------------------------------------- 0 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(-180, -90, 0, 0)) 1 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(-180, 0, 0, 90)) 2 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(0, -90, 180, 0)) 3 SDO_GEOMETRY(2003, 8307, NULL, SDO_ELEM_INFO_ARRAY(1, 1003, 3), SDO_ORDINATE_ARR AY(0, 0, 180, 90)) 4 rows selected.
Parent topic: SDO_SAM Package (Spatial Analysis and Mining)