DML Statements(Insert,Update,Delete)

Out of all the 3 DML statements, delete requires more space in the undo.dbf

Without undo, we can not perform the DML operations.

In case of Insert, oracle keeps the rowid in the undo segments.

In case of Update, oracle keeps the past image in the undo segments.

In case of Delete, oracle keeps the entire row data in the undo segments.

Every row in a block has rowid, which is 18 digit hexadecimal format in nature.