alter_command
::= alter_cluster
| alter_database
| alter_index
| alter_profile
| alter_cost
| alter_role
| alter_rollback
| alter_sequence
| alter_session
| alter_snapshot
| alter_snapshot_log
| alter_system
| alter_table
| alter_tablespace
| alter_trigger
| alter_user
| alter_view
This rule is called by