Explanation/Reference:
Explanation:
E: By default, flashback archiving is disabled for any table. You can enable flashback archiving for a table if you have the FLASHBACK ARCHIVE object privilege on the Flashback Data Archive that you want to use for that table.
D: Creating a Flashback Data Archive
/Create a Flashback Data Archive with the CREATE FLASHBACK ARCHIVE statement, specifying the following:
Name of the Flashback Data Archive
Name of the first tablespace of the Flashback Data Archive
(Optional) Maximum amount of space that the Flashback Data Archive can use in the first tablespace
/Create a Flashback Data Archive named fla2 that uses tablespace tbs2, whose data will be retained for two years:
CREATE FLASHBACK ARCHIVE fla2 TABLESPACE tbs2 RETENTION 2 YEAR;

Explanation/Reference:
Explanation:
RMAN> ALTER TABLESPACE sysaux OFFLINE IMMEDIATE;
RMAN> RESTORE TABLESPACE sysaux;
RMAN> RECOVER TABLESPACE sysaux;
RMAN> ALTER TABLESPACE sysaux ONLINE;
* Example:
While evaluating the 12c beta3 I was not able to do the recover while testing "all pdb files lost".
Cannot close the pdb as the system datafile was missing...
So only option to recover was:
Shutdown cdb (10)
startup mount; (1)
restore pluggable database
recover pluggable database
alter database open;
alter pluggable database name open;
Oracle support says: You should be able to close the pdb and restore/recover the system tablespace of PDB.
* Inconsistent backups are usually created by taking online database backups. You can also make an inconsistent backup by backing up data files while a database is closed, either:
/Immediately after the crash of an Oracle instance (or, in an Oracle RAC configuration, all instances)
/After shutting down the database using SHUTDOWN ABORT
Inconsistent backups are only useful if the database is in ARCHIVELOG mode and all archived redo logs created since the backup are available.
* Open the database with the RESETLOGS option after finishing recovery:
SQL> ALTER DATABASE OPEN RESETLOGS;

Explanation
A: In certain situations, you may want to exclude selected columns or tables from scanning or conversion steps of the migration process.
D: Exceed column limit
The cell data will not fit into a column after conversion.
E: Need conversion
The cell data needs to be converted, because its binary representation in the target character set is different than the representation in the current character set, but neither length limit issues nor invalid representation issues have been found.
* Oracle Database Migration Assistant for Unicode (DMU) is a unique next-generation migration tool providing an end-to-end solution for migrating your databases from legacy encodings to Unicode.

Explanation
Oracle 11g/12c makes further use of SQL tuning sets with the SQL Performance Analyzer, which compares the performance of the statements in a tuning set before and after a database change. The database change can be as major or minor as you like, such as: