db_to_csv: 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 CentOS possible default full paths are:

/usr/bin/db_to_csv - from package: perl-Fsdb

You may install the required package with command yum install {package}

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