Note: The following description applies both to Postgres-XC and PostgreSQL if not described explicitly.
DROP TABLE removes tables from the database. Only its owner can drop a table. To empty a table of rows without destroying the table, use DELETE or TRUNCATE.
DROP TABLE always removes any indexes, rules, triggers, and constraints that exist for the target table. However, to drop a table that is referenced by a view or a foreign-key constraint of another table, CASCADE must be specified. (CASCADE will remove a dependent view entirely, but in the foreign-key case it will only remove the foreign-key constraint, not the other table entirely.)
Do not throw an error if the table does not exist. A notice is issued in this case.
The name (optionally schema-qualified) of the table to drop.
Automatically drop objects that depend on the table (such as views).
Refuse to drop the table if any objects depend on it. This is the default.