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.

There are a number of restrictions for flashback archives: The tablespaces used for a flashback archive must use local extent management and automatic segment space management. The database must use automatic undo management.

References:

Configuring Backup Duplexing You can use the CONFIGURE ... BACKUP COPIES command to specify how many copies of each backup piece should be created on the specified device type for the specified type of file. This type of backup is known as a duplexed backup set. The CONFIGURE settings for duplexing only affect backups of datafiles, control files, and archived logs into backup sets, and do not affect image copies. NOT A The CONFIGURE MAXSETSIZE command limits the size of backup sets created on a channel. This CONFIGURE setting applies to any channel, whether manually allocated or configured, when the BACKUP command is used to create backup sets. The default value is given in bytes and is rounded down to the lowest kilobyte value.