2.6 Point Cloud-Related Object Types
This topic describes the following object types related to support for point clouds.
Note:
Point cloud object types are not supported in Oracle Autonomous Database Serverless deployments.Parent topic: Spatial Data Types and Metadata
2.6.1 SDO_PC Object Type
The description of a point cloud is stored in a single row, in a single column of object type SDO_PC in a user-defined table. The object type SDO_PC is defined as:
CREATE TYPE sdo_pc AS OBJECT (base_table VARCHAR2(70), base_table_col VARCHAR2(1024), pc_id NUMBER. blk_table VARCHAR2(70), ptn_params VARCHAR2(1024), pc_extent SDO_GEOMETRY, pc_tol NUMBER, pc_tot_dimensions NUMBER, pc_domain SDO_ORGSCL_TYPE, pc_val_attr_tables SDO_STRING_ARRAY, pc_other_attrs XMLTYPE);
The SDO_PC type has the attributes shown in Table 2-8.
Table 2-8 SDO_PC Type Attributes
Attribute | Explanation |
---|---|
BASE_TABLE |
Name of the base table containing a column of type SDO_PC |
BASE_TABLE_COL |
Name of the column of type SDO_PC in the base table |
PC_ID |
ID number for the point cloud. (This unique ID number is generated by Spatial. It is unique within the schema for base tables containing a column of type SDO_PC.) |
BLK_TABLE |
Name of the table that contains information about each block in the point cloud. This table contains the columns shown in Table 2-9. |
PTN_PARAMS |
Parameters for partitioning the point cloud |
PC_EXTENT |
SDO_GEOMETRY object representing the spatial extent of the point cloud (the minimum bounding object enclosing all objects in the point cloud) |
PC_TOL |
Tolerance value for points in the point cloud. (For information about spatial tolerance, see Tolerance.) |
PC_TOT_DIMENSIONS |
Total number of dimensions in the point cloud. Includes spatial dimensions and any nonspatial dimensions, up to a maximum total of 9. |
PC_DOMAINS |
(Not currently used.) |
PC_VAL_ATTR_TABLES |
SDO_STRING_ARRAY object specifying the names of any value attribute tables for the point cloud. Type SDO_STRING_ARRAY is defined as |
PC_OTHER_ATTRS |
XMLTYPE object specifying any other attributes of the point cloud. (For more information, see the Usage Notes for the SDO_PC_PKG.INIT function.) |
The point cloud block table (specified in the BLK_TABLE attribute of the SDO_PC type) contains the columns shown in Table 2-9.
Table 2-9 Columns in the Point Cloud Block Table
Column Name | Data Type | Purpose |
---|---|---|
OBJ_ID |
NUMBER |
ID number of the point cloud object. |
BLK_ID |
NUMBER |
ID number of the block. |
BLK_EXTENT |
SDO_GEOMETRY |
Spatial extent of the block. |
BLK_DOMAIN |
SDO_ORGSCL_TYPE |
(Not currently used.) |
PCBLK_MIN_RES |
NUMBER |
For point cloud data, the minimum resolution level at which the block is visible in a query. The block is retrieved only if the query window intersects the spatial extent of the block and if the minimum - maximum resolution interval of the block intersects the minimum - maximum resolution interval of the query. Usually, lower values mean farther from the view point, and higher values mean closer to the view point. |
PCBLK_MAX_RES |
NUMBER |
For point cloud data, the maximum resolution level at which the block is visible in a query. The block is retrieved only if the query window intersects the spatial extent of the block and if the minimum - maximum resolution interval of the block intersects the minimum - maximum resolution interval of the query. Usually, lower values mean farther from the view point, and higher values mean closer to the view point. |
NUM_POINTS |
NUMBER |
For point cloud data, the total number of points in the POINTS BLOB |
NUM_UNSORTED_POINTS |
NUMBER |
For point cloud data, the number of unsorted points in the POINTS BLOB |
PT_SORT_DIM |
NUMBER |
Number of the dimension (1 for the first dimension, 2 for the second dimension, and so on) on which the points are sorted. |
POINTS |
BLOB |
BLOB containing the points. Consists of an array of points, with the following information for each point:
|
You can use an attribute name in a query on an object of SDO_PC. Example 2-7 shows part of a SELECT statement that queries the PC_EXTENT attribute of the OCEAN_FLOOR column of a hypothetical OCEAN_FLOOR_MODEL table.
Example 2-7 SDO_PC Attribute in a Query
SELECT o.ocean_floor.pc_extent FROM ocean_floor_model o WHERE ...;
Parent topic: Point Cloud-Related Object Types
2.6.2 SDO_PC_BLK_TYPE and SDO_PC_BLK Object Type
When you perform a clip operation using the SDO_PC_PKG.CLIP_PC function, an object of SDO_PC_BLK_TYPE is returned, which is defined as TABLE OF SDO_PC_BLK
.
The attributes of the SDO_PC_BLK object type are the same as the columns in the point cloud block table, which is described in Table 2-9 in SDO_PC Object Type.
Parent topic: Point Cloud-Related Object Types