Displaying tags with many messages very slow in Emacs

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Hello,

I am planning to have some tags with more than 10k messages, and I am experiencing very slow list display in emacs.

Installation on OS X 10.6, using brew: notmuch 0.9, chert database format. Emacs 24.0.90.1 on iMac, intel 2.8 Ghz i7, 8Gb ram.

Testing 'notmuch new' on a Maildir folder with about 30000 messages (about one fourth of my archive).

At beginning notmuch was indexing about 200 msgs/sec. The more it indexed, the slower it became. After about 20000 msgs it slowed down to 70 msgs/sec. I am not sure if that is a behaviour due to Xapian.

Anyway, after initial indexing, starting notmuch from emacs, I have:

"Welcome to notmuch. You have 34,366 messages."

Once I start browsing the inbox (34,208), Emacs displays the initial screenful, but the whole list takes quite a while to load, about 2 minutes. After that time, in the status bar I see "Top of 2M".

That happens every time I am browsing the inbox, in order to assign proper tags.

The real issue, though, is that scrolling down the list has a noticeable delay, enough to make it basically unusable.

Is there something I do not know that I should do to improve that speed (either from within Emacs, or in notmuch config file?

I would be very grateful for any advice or pointer on how to speed up the notmuch experience.


Thank you,

Sam