If you prefer sqlplus not installed yet, install Oracle Instant Client separately, or use the SQL*Plus included in the XE installation:

sudo systemctl enable oracle-xe-21c Connect as SYSTEM :

[Unit] Description=Oracle Database 21c XE After=network.target [Service] Type=forking ExecStart=/etc/init.d/oracle-xe-21c start ExecStop=/etc/init.d/oracle-xe-21c stop ExecReload=/etc/init.d/oracle-xe-21c restart User=oracle Group=oracle Restart=no

wget https://download.oracle.com/otn-pub/otn_software/db-express/oracle-database-xe-21c-1.0-1.ol8.x86_64.rpm If the link fails, go to https://www.oracle.com/database/technologies/xe-downloads.html , accept the license, and copy the download URL for the . Step 3: Convert RPM to DEB sudo alien --scripts --to-deb oracle-database-xe-21c-1.0-1.ol8.x86_64.rpm This creates a .deb file (e.g., oracle-database-xe-21c_1.0-2_amd64.deb ). Step 4: Install the DEB Package sudo dpkg --install oracle-database-xe-21c_1.0-2_amd64.deb If you get dependency errors, run:

export ORACLE_HOME=/opt/oracle/product/21c/dbhomeXE export ORACLE_SID=XE export PATH=$PATH:$ORACLE_HOME/bin Apply changes:

source ~/.bashrc # Start sudo /etc/init.d/oracle-xe-21c start Stop sudo /etc/init.d/oracle-xe-21c stop Status sudo /etc/init.d/oracle-xe-21c status