Note in the example above that when you start SQL*Plus,
you must provide the name of the user account. In this case, we logged into the
account john_dba. Next, SQL*Plus will prompt you for the password to this
account. If you enter the correct password (you will not be able to see the
password when you enter it in) then Oracle will pass you to the SQL prompt
(SQL>).
You can also include the password when you call
SQL*Plus, but this means that your password will not be hidden, and this can
have serious security implications. Here is an example of using the user account
and the password to log into SQL*Plus:
/u01/app> sqlplus john_dba/my_password
If you do this in a UNIX/Linux environment, the command
“ps –ef” will display your password for anyone to see.
To perform specific DBA activities on the database (such
as backing up the database or shutting it down), you will need to log in as a
special type of user. This is because these operations require a special set of
administrative privileges called the SYSDBA and SYSOPER privileges.
To activate these privileges, your user ID must be
allowed to access these privileges (we will discuss setting up such an account
later in this book) and you must use a special connection string to connect to
the database to activate these privileges. If you want to connect using the
SYSDBA privileges (these are super DBA privileges) then use the following
syntax:
C:\>sqlplus “sys as sysdba”
You can also include the password if you prefer:
C:\>sqlplus “sys/my_password as sysdba”
The same method of connecting also works with the
SYSOPER privilege. You simply replace sysdba with sysoper in the connection
string. One final thing to notice is that the connection string is enclosed in
quotes. This is required because there is white space (blanks) inside the
connection string.
Oracle SQL*Plus Concepts
DBA’s and developers are the most common users of
SQL*Plus, and database management is frequently performed from SQL*Plus. SQL
stands for Structured Query Language. It is the language that you use to
communicate with Oracle, and it is the language you will use in SQL*Plus. You
will see lots of examples of SQL in this book, and we will discuss them in
detail when we come to them, so don’t worry about the specifics of the language
just now.
The following activities are examples of the things that
a DBA will do from SQL*Plus:
* Create, Drop and alter database objects
* Startup and shutdown the database
* Create, Drop and alter database users
* Manage database security
* Manage database backup and recovery operations
The SQL *Plus prompt is also used to access the data
within the Oracle database. DBA’s, developers and even end-users will use
SQL*Plus to execute database queries using the SQL language.
This is an excerpt from the bestselling "Easy
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