With adaptive SQL plan management, DBAs no longer have to manually run the verification or evolve process for non-accepted plans. When automatic SQL tuning is in COMPREHENSIVE mode, it runs a verification or evolve process for all SQL statements that have non-accepted plans during the nightly maintenance window. If the non-accepted plan performs better than the existing accepted plan (or plans) in the SQL plan baseline, then the plan is automatically accepted and becomes usable by the optimizer. After the verification is complete, a persistent report is generated detailing how the non-accepted plan performs compared to the accepted plan performance. Because the evolve process is now an AUTOTASK, DBAs can also schedule their own evolve job at end time.
Note:
*The optimizer is able to adapt plans on the fly by predetermining multiple subplans for portions of the plan.
*Adaptive plans, introduced in Oracle Database 12c, enable the optimizer to defer the final plan decisionfor a statement until execution time. The optimizer instruments its chosen plan (the default plan) withstatistics collectors so that it can detect at runtime, if its cardinality estimates differ greatly from theactual number of rows seen by the operations in the plan. If there is a significant difference, then theplan or a portion of it will be automatically adapted to avoid suboptimal performance on the firstexecution of a SQL statement.

Explanation
Asynchronous Global Index Maintenance for DROP and TRUNCATE PARTITION
This feature enables global index maintenance to be delayed and decoupled from a DROP and TRUNCATE partition without making a global index unusable. Enhancements include faster DROP and TRUNCATE partition operations and the ability to delay index maintenance to off-peak time.

A:When SYSDBA or SYSOPER privileges are granted to a user, that user's
name and privilege information are added to the password file.
C:Creating a password file via orapwd enables remote users to connect with administrative
privileges through SQL*Net.
Not E:The Oracle orapwd command line utility assists the DBA with granting SYSDBA and
SYSOPER privileges to other users.
*You can create a password file using the password file creation utility, ORAPWD. For
some operating systems, you can create this file as part of your standard installation.
*ORAPWD FILE=filename [ENTRIES=numusers]
[FORCE={Y|N}] [IGNORECASE={Y|N}] [NOSYSDBA={Y|N}]
FILEName to assign to the password file. See your operating system documentation for
name requirements. You must supply a complete path. If you supply only a file name, the
file is written to the current directory.
ENTRIES(Optional) Maximum number of entries (user accounts) to permit in the file.
FORCE(Optional) If y, permits overwriting an existing password file.
IGNORECASE(Optional) If y, passwords are treated as case-insensitive.
NOSYSDBA(Optional) For Data Vault installations. See the Data Vault installation guide for
your platform for more information.

* Data Recovery Advisor can diagnose failures such as the following:
/ (B) Components such as datafiles and control files that are not accessible because they do not exist, do not have the correct access permissions, have been taken offline, and so on
/ (A, E) Physical corruptions such as block checksum failures and invalid block header field values
/ Inconsistencies such as a datafile that is older than other database files
/ I/O failures such as hardware errors, operating system driver failures, and exceeding operating system resource limits (for example, the number of open files)
* The Data Recovery Advisor automatically diagnoses corruption or loss of persistent data on disk, determines the appropriate repair options, and executes repairs at the user's request. This reduces the complexity of recovery process, thereby reducing the Mean Time To Recover (MTTR).