preludedb-admin: 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/preludedb-admin - from package: libpreludedb0

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

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