单项选择题
A. It returns versions of rows only within a transaction.
B. It can be used in subqueries contained only in a SELECT statement.
C. It will return an error if the undo retention time is less than the lower bound time or SCN specified.
D. It retrieves all versions including the deleted as well as subsequently reinserted versions of the rows.
单项选择题 Evaluate the following statement： Which statement is true regarding the evaluation of rows returned by the subquery in the INSERT statement？（）
单项选择题 EMPDET is an external table containing the columns EMPNO and ENAME. Which command would work in relation to the EMPDET table？（）
多项选择题 WhichthreepossiblevaluescanbesetfortheTIME_ZONEsessionparameterbyusingtheALTERSESSIONcommand？（）