Tables
Usually you will only be creating tables for storing PcPatch
objects, and
using PcPoint
objects as transitional objects for filtering, but it is
possible to create tables of both types. PcPatch
and PcPoint
columns
both require an argument that indicate the pcid that will be used to interpret
the column.
-- This example requires the schema entry from the previous
-- section to be loaded so that pcid==1 exists.
-- A table of points
CREATE TABLE points (
id SERIAL PRIMARY KEY,
pt PCPOINT(1)
);
-- A table of patches
CREATE TABLE patches (
id SERIAL PRIMARY KEY,
pa PCPATCH(1)
);
In addition to any tables you create, you will find two other system-provided point cloud tables:
the
pointcloud_formats
table that holds all the pcid entries and schema documentsthe
pointcloud_columns
view, that displays all the columns in your database that contain point cloud objects
Now that you have created two tables, you’ll see entries for them in the
pointcloud_columns
view:
SELECT * FROM pointcloud_columns;
schema | table | column | pcid | srid | type
--------+-------------+--------+------+------+---------
public | points | pt | 1 | 4326 | pcpoint
public | patches | pa | 1 | 4326 | pcpatch