Hi Jason,
On Mon, Jul 11, 2011 at 03:07:21PM -0400, Jason Woofenden wrote:
> notmuch search tag:foo is slow!
> 
yes, i've just used the vim ui for the first time and i agreee, its sluggish,
searching for * takes a while.

> (when my e-mail files are not already in the disk cache)
> 
> I saw on my activity monitor applet that it was using mostly i/o,
> and started to wonder if it was opening every e-mail. I little work
> with strace and searching revealed that this command was opening
> many many e-mail files from my maildir(s). I spent a little while
> digging around in the notmuch source, and didn't see where it was
> opening the email files.

I cannot reproduce this. I'm no expert, but at least the output of 
 strace vim -c ":NotMuch" 2>log
does not contain any path that matches that of my maildir.
Also, I wout be surprised if all individual mails would be read,
because for this, a search for all messages feels too fast.

> 2) Do you agree that it should instead get this information from
> the database?
agreed. And If the mail files get read on every search for you,
something is definately going wrong there.

A quick browse through notmuch.vim tells me that 
1) it doesn't use notmuchs json output, i think it should, as iirc
this api is considered 'more stable' and is easier to parse than the 
default output. More importantly,
2) the output of notmuch is copied into a list. This will of course
be slow if your query matches a lot of messages. Could this be done
by asyncronously writing to the buffer somehow?

best,
/p