By default in sqlplus , you can not use special keystrokes such Ctrl-R to look for previous typed SQL requests.
Within Debian, there is a package named rlwrap, which gives you the features that sqlplus does not have.
To install it :
root@localhost:~# apt-get install rlwrap
To use it as a non-root user, add an alias to your .bashrc file : alias sqlplus=’rlwrap sqlplus’
fool@localhost:~$ source .bashrc
And then, sqlplus is again available with new features.