optimize: 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 Debian possible default full paths are:

/usr/share/solr/bin/optimize - from package: solr-common

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

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