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 documents
- the 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