Oracle notes (III), SQL * Plus

1. Account Logon
C: \> sqlplus "sys/love2you as sysdba"

C: \> sqlplus/nolog
SQL> connect sys/love2you as sysdba

2. Start and close the instance

● SQL> startup
Start the instance, open the control file, and open the data file

● SQL> startup Mount
Start the instance and open the control file

● SQL> startup nomount
Start an instance

● SQL> shutdown immediate
Force all users to disconnect and shut down the server after executing the current SQL statement.

● SQL> Shutdown
Wait for all users to disconnect and close the server.

3. SQL * Plus execution plan
Oracle only schedules one query plan in the form of substitution variables to improve statement execution efficiency.

SQL> select * from Dept where deptno = & TT
Enter value for TT: 10
....

SQL> select * from Dept where deptno = & TT
Enter value for TT: 20