pgcompact: 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/pgcompact - from package: pgtoolkit

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

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