imposm-psqldb: 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/bin/imposm-psqldb - from package: imposm

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

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