Note: XCONLY: The following description applies only to Postgres-XC.
DROP NODE is new SQL query specific to Postgres-XC since 0.9.7 that deletes cluster node information in catalog pgxc_node.
Node connection that has been deleted does not guarranty that connection information cached in pooler is updated accordingly.
DROP NODE only runs on the local node where it is launched.
DROP NODE does not conform to the SQL standards, it is a Postgres-XC specific command.