单选题Examine the command： ALTER DATABASE ADD SUPPLEMENTAL LOG DATA （PRIMARY KEY） COLUMNS； What does the command accomplish？（）A Creates an additional copy of the database online redo log files. B Stores the primary key column values of each row involved
题目
单选题
Examine the command： ALTER DATABASE ADD SUPPLEMENTAL LOG DATA （PRIMARY KEY） COLUMNS； What does the command accomplish？（）
A
Creates an additional copy of the database online redo log files.
B
Stores the primary key column values of each row involved in a DML operation in the online redo log files.
C
Stores the primary key column values of each row involved in a DML operation in the supplemental log files.
D
Stores the old and new primary key column values of each row involved in a DML operation only when the primary key is modified in the online redo log files.