Explanation/Reference:
Explanation:
* orapwd
/You can create a database password file using the password file creation utility, ORAPWD.
The syntax of the ORAPWD command is as follows:
orapwd FILE=filename [ENTRIES=numusers] [FORCE={y|n}] [ASM={y|n}]
[DBUNIQUENAME=dbname] [FORMAT={12|legacy}] [SYSBACKUP={y|n}] [SYSDG={y|n}]
[SYSKM={y|n}] [DELETE={y|n}] [INPUT_FILE=input-fname]
force - whether to overwrite existing file (optional),
* v$PWFILE_users
/12c: V$PWFILE_USERS lists all users in the password file, and indicates whether the user has been granted the SYSDBA, SYSOPER, SYSASM, SYSBACKUP, SYSDG, and SYSKM privileges.
/10c: sts users who have been granted SYSDBA and SYSOPER privileges as derived from the password file.
ColumnDatatypeDescription
USERNAMEVARCHAR2(30)The name of the user that is contained in the password file SYSDBAVARCHAR2(5)If TRUE, the user can connect with SYSDBA privileges
SYSOPERVARCHAR2(5)If TRUE, the user can connect with SYSOPER privileges Incorrect:
not E: The format of the v$PWFILE_users file is already in 12c format.

Explanation
Explanation/Reference:
References: https://docs.oracle.com/database/121/LADBI/oraclerestart.htm#LADBI999

* 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).