单项选择题
A. The VERSIONS BETWEEN clause may be used in DML statements.
B. The VERSIONS BETWEEN clause may be used in DDL statements.
C. The VERSIONS BETWEEN clause may not be used to query past DDL changes to tables.
D. The VERSIONS BETWEEN clause may not be used to query past DML statements to tables.
单项选择题 At the request of a user， you issue the following command to restore a dropped table： flashback table "BIN$F2JFfMq8Q5unbC0ceE9eJg==$0" to before drop； Later， the user notifies you that the data in the table seems to be very old and out of date. What might be the problem？（）
多项选择题 WhichofthefollowingcanbeusedinconjunctionwithaFlashbackVersionsQuerytofiltertheresults？（）
单项选择题 WhichpseudocolumncouldyouusetoidentifyauniquerowinaFlashbackVersionsQuery？（）