dbcolmerge: 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/dbcolmerge - from package: perl-Fsdb

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

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