pg_view: 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/pg_view - from package: pg_view

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

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