relational-cli: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/relational-cli - from package: relational-cli

You may install the required package with command apt-get install {package}
Error in other languages:
relational-cli: bevel nie gevind nie
relational-cli: comandă negăsită
relational-cli: comando não encontrado
relational-cli: commande introuvable
relational-cli: command not found
relational-cli: käsku ei ole
relational-cli: không tìm thấy lệnh
relational-cli: komanda nerasta
relational-cli: Kommando nicht gefunden.
relational-cli: kommandot finns inte
relational-cli: komut yok
relational-cli: nie znaleziono polecenia
relational-cli: níor aimsíodh an t-ordú
relational-cli: no se encontró la orden
relational-cli: no s'ha trobat l'ordre
relational-cli: opdracht niet gevonden
relational-cli: parancs nem található
relational-cli: perintah tidak ditemukan
relational-cli: príkaz nenájdený
relational-cli: příkaz nenalezen
relational-cli: команда не найдена
relational-cli: командата не е открита
relational-cli: 命令找不到
relational-cli: コマンドが見つかりません