■作成
su postgres
create [UserName]

error while loading shared libraries: libreadline.so.5: cannot open shared object file: No such file or directory
といったエラー
libreadline.so.5は、/usr/local/lib配下
export LD_LIBRARY_PATH=”$LD_LIBRARY_PATH”:/usr/local/lib する。

再度実行
create [UserName]
could not change directory to “/home/[UserName]”
Shall the new role be a superuser? (y/n) n
Shall the new role be allowed to create databases? (y/n) y
Shall the new role be allowed to create more new roles? (y/n) n
CREATE ROLE

■削除
dropuser [UserName]