Questions about conn / as sysdba can be connected directly without a password
May 6, 2015 14:12:36 weivi001 Reads: 12928 Tags: the Oracle More
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SQL> conn /as sysdba;
Connected.
SQL> show user;
USER is "SYS"
sqlplus / nolog, conn / as sysdba been able to log on, that way when the oracle authentication login. You can try this: sqlplus / nolog, conn abcd / sss as sysdba, you can find a successful login.
2 oracle when you log in, there are three authentication methods: operating system authentication, password file authentication database authentication. The conn / as sysdba is part of the operating system certification. Nanjing Oracle Training
Why do you say that? Your current user logged on when the computer is turned on, that is, into the user's operating system, for example, gooooal, it ora_dba your computer in the group.
You can right in the "My Computer" click, find the "management", select "Local Users and Groups", found a group called "ora_dba", double-click it to see the member list has "gooooal".
That is, operating system verification in conn / as sysdba, oracle will find your user currently logged on ora_dba belong to the group, and therefore can log in successfully.
You can put ora_dba group "gooooal" the user to delete, and then conn / as sysdba, found the entrance.
3 password file validation can access relevant information, Baidu oracle authentication method, can be found on the relevant information.
4 In fact, under linux or unix environment, installation oracle is to set a lot of things, such as setting user and user groups, etc., unlike in the windows, the installation of a fool.
5 About the security, if the oracle installed locally, in fact, is your local oracle server, so the higher authority. You start with which user oracle instance? Which user to mount the database? Which user to open the database? Sql select, etc. After thus be able to operate?
In instances such as when the oracle has not yet started, oracle database built a user certainly can not be used. Why it has operating system authentication. With this user to start oracle instance, reproduced databases. Before you can make additions and deletions to change search oracle table.
In ORACLE, sqlplus / as sysdba intermediate as slashes and spaces. sqlplus / nolog command, but no spaces, why?
sqlplus / as sysdba is a simplified wording, in fact, is omitted username and password, complete wording is sqlplus sys / password as sysdba and sqlplus / nolog is another usage of, nolog means no login, just enter sqlplus software only
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