Which two statements regarding the Flashback Table feature are correct? (Choose two.)
A.
Flashback Table can be performed on system tables.
B.
Flashback Table operation does not shrink the segments.
C.
Flashback Table uses log mining to extract SQL_REDO and SQL_UNDO statements.
D.
Flashback Table operation acquires exclusive data manipulation language (DML) locks.
Explanation:
Semantics
During an Oracle Flashback Table operation, Oracle Database acquires exclusive DML locks on all the tables
specified in the Flashback list. These locks prevent any operations on the tables while they are revertingto their
earlier state.Restrictions on Flashing Back Tables
This statement is subject to the following restrictions:
Flashback Table operations are not valid for the following type objects: tables that are part of a cluster,
materialized views, Advanced Queuing (AQ) tables, static data dictionary tables, system tables, remote tables,
object tables, nested tables, or individual table partitions or subpartitions.
The following DDL operations change the structure of a table, so that you cannot subsequently use the TO SCN
or TO TIMESTAMP clause to flash the table back to a time preceding the operation: upgrading, moving, or
truncating a table; adding a constraint to a table, adding a table to a cluster; modifying or dropping a column;
changing a column encryption key; adding, dropping, merging, splitting, coalescing, or truncating a partition or
subpartition (with the exception of adding a range partition).