If an administrative user belongs to the “dba” group on Unix, or the “ORA_DBA” (ORA_sid_DBA)
group on NT, he/she can connect like this:
connect / as sysdba
No password is required. This is equivalent to the desupported “connect internal” method.
A password is required for “non-secure” administrative access. These passwords are stored in password files. Remote connections via Net8 are classified as non-secure.
Look at this example:
connect sys/password as sysdba.

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