In SQL*Plus, how do I change the prompt to show the connected user and database?

#Connect as oracle user and add the following line at the end of th glogin.sql script.

su - oracle
vi $ORACLE_HOME\sqlplus\admin\glogin.sql
set sqlprompt "_user '@' _connect_identifier > " 

#Now check

sqlplus / as sysdba

Crontab -e You (oracle) are not allowed to use this program (crontab)

$ crontab -e
You (oracle) are not allowed to use this program (crontab)
See crontab(1) for more information

# The following files control crontab usage


# Go to the root user and add oracle user to the following file:

echo oracle > /etc/cron.allow

# Or delete oracle from /etc/cron.deny file. 🙂