pgbench: 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/pgbench - from package: postgresql-contrib

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

On Debian possible default full paths are:

/usr/bin/pgbench - from package: postgresql-client-common
/usr/lib/postgresql/9.4/bin/pgbench - from package: postgresql-contrib-9.4

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

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