polygraph-cdb: 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/polygraph-cdb - from package: polygraph

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