Installation of Org-ref slows down start-up

Question

I am super new to Emacs. I just followed the installation section of org-ref. I managed to get a simple citation working by adding bibliographystyle:plain to the file. This is one of the solution one user posted on an issue on Github.

I noticed that the process of startup is slowed down after I added the following lines to the configuration:

;; Melpa configuration
(require 'package)
(let* ((no-ssl (and (memq system-type '(windows-nt ms-dos))
                    (not (gnutls-available-p))))
       (proto (if no-ssl "http" "https")))
  (when no-ssl
    (warn "\
Your version of Emacs does not support SSL connections,
which is unsafe because it allows man-in-the-middle attacks.
There are two things you can do about this warning:
1. Install an Emacs version that does support SSL and be safe.
2. Remove this warning from your init file so you won't see it again."))
  ;; Comment/uncomment these two lines to enable/disable MELPA and MELPA Stable as desired
  (add-to-list 'package-archives (cons "melpa" (concat proto "://melpa.org/packages/")) t)
  ;;(add-to-list 'package-archives (cons "melpa-stable" (concat proto "://stable.melpa.org/packages/")) t)
  (when (< emacs-major-version 24)
    ;; For important compatibility libraries like cl-lib
    (add-to-list 'package-archives (cons "gnu" (concat proto "://elpa.gnu.org/packages/")))))
(package-initialize)

;; org-ref configuration

(setq reftex-default-bibliography '("~/Dropbox/bibliography/references.bib"))

;; see org-ref for use of these variables
(setq org-ref-bibliography-notes "~/Dropbox/bibliography/notes.org"
      org-ref-default-bibliography '("~/Dropbox/bibliography/references.bib")
      org-ref-pdf-directory "~/Dropbox/bibliography/bibtex-pdfs/")

(setq bibtex-completion-bibliography "~/Dropbox/bibliography/references.bib"
      bibtex-completion-library-path "~/Dropbox/bibliography/bibtex-pdfs"
      bibtex-completion-notes-path "~/Dropbox/bibliography/helm-bibtex-notes")

;; open pdf with system pdf viewer (works on mac)
(setq bibtex-completion-pdf-open-function
  (lambda (fpath)
    (start-process "open" "*open*" "open" fpath)))

;; alternative
;; (setq bibtex-completion-pdf-open-function 'org-open-file)

(setq org-latex-pdf-process (list "latexmk -shell-escape -bibtex -f -pdf %f"))

(require 'org-ref)

Should I remove any of these from the configuration file? Or the slow down is unavoidable?

Answer 1

The (require 'org-ref) means that org-ref will be loaded at every startup, which also likely means that all of Org will be loaded at startup.

You shouldn't need that. More specifically, the org-ref package should automatically arrange to be loaded when you use it, so if it's properly packaged, this require is simply superfluous.