org-refile-use-cache

org-refile-use-cache is a variable defined in `org.el'.
Its value is

nil

Documentation:
Non-nil means cache refile targets to speed up the process.
The cache for a particular file will be updated automatically when
the buffer has been killed, or when any of the marker used for flagging
refile targets no longer points at a live buffer.
If you have added new entries to a buffer that might themselves be targets,
you need to clear the cache manually by pressing `C-0 C-c C-w' or, if you
find that easier, `C-u C-u C-u C-c C-w'.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.1 of Emacs.