单项选择题

Which of the following statements is true regarding the VERSIONS BETWEEN clause？（）

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.

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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to before drop； Later， the user notifies you that the data in the table seems to be very old and out of date.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？（）

A. Because a proper range of SCNs was not specified， the wrong data was restored.
B. A proper range of timestamps was not specified， so the wrong data was restored.
C. A previous Flashback Drop operation had been performed， resulting in multiple versions of the table being stored in the Recycle Bin.
D. Either option A or B could be correct. Not enough information was provided to determine which.
E. None of the above.

多项选择题WhichofthefollowingcanbeusedinconjunctionwithaFlashbackVersionsQuerytofiltertheresults？（）

A. A range of SCN values
B. A list of SCN values
C. A starting and ending timestamp
D. Minimum and maximum sequence values
E. A list of sequence values

单项选择题WhichpseudocolumncouldyouusetoidentifyauniquerowinaFlashbackVersionsQuery？（）

A. XID
B. VERSIONS_PK
C. VERSIONS_XID
D. VERSIONS_UNIQUE

单项选择题WhichofthefollowingstatementsbestdescribesFlashbackVersionsQuery？（）

A. Flashback Versions Query is used to make changes to multiple versions of data that existed between two points in time.
B. Flashback Versions Query is used to view all version changes on rows that existed between the time the query was executed and a point in time in the past.
C. Flashback Versions Query is used to view version changes and the SQL to undo those changes on rows that existed between two points in time.
D. Flashback Versions Query is used to view all version changes on rows that existed between two points in time.

多项选择题Users notify you that their application is failing every time they try to add new records. Because of poor application design， the actual ORA error message is unavailable. What might be the problem？（）

A. The application user has exceeded their undo quota.
B. The FLASHBACK GUARANTEE option is set on the undo tablespace.
C. The table is currently being queried by a Flashback Transaction Query operation.
D. The table is currently being queried by a Flashback Versions Query operation.
E. The RETENTION GUARANTEE option is set on the undo tablespace.