stardiviner wrote:
> I setup default =ac-sources= for auto-complete like this:
>
> #+BEGIN_SRC emacs-lisp
> (setq-default ac-sources
>               '(ac-source-yasnippet
>                 ac-source-abbrev
>                 ac-source-filename
>                 ac-source-files-in-current-dir
>                 ac-source-dictionary
>                 ac-source-words-in-same-mode-buffers
>                 ))
> #+END_SRC
>
> And I found =ac-source-dictionary= and =ac-source-words-in-same-mode-buffers= is
> heavy for Org-mode, So I try to remove them only in Org-mode.

Do you have some evidence of this?  Profiling with/without?  It'd be
interesting.

Other point: I'm surprised you don't have the source
`ac-source-words-in-buffer' (maybe instead of
`ac-source-words-in-same-mode-buffers')...

Best regards,
  Seb

--
Sebastien Vauban