Which three descriptions are correct about the effects of the TRUNCATE command on a table（）

• A、The corresponding indexes for the table are also truncated.
• B、Delete triggers on the table are fired during the execution of the TRUNCATE command.
• C、The child table is truncated when the TRUNCATE command is applied on the parent table.
• D、The high-water mark （HWM） is set to point to the first usable data block in the table segment.
• E、No undo or very little undo data is generated during the execution of the TRUNCATE command