showdb: command not found

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/showdb - from package: emboss

You may install the required package with command apt-get install {package}

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