Hello,

If notmuch-hello includes a saved search with a slow query, switching to
a notmuch-hello buffer is very slow due to notmuch-mode updating counts
for search results. mjw1009 suggested "(setq notmuch-hello-auto-refresh
nil)", which stops the counting and works around the problem.

Fundamentally, the problem is a slow query. On my laptop (Thinkpad T60),
many things are pretty much instant, even though I have a HDD, no SSD:

> ; time notmuch count 'tag:inbox and tag:list'
> 25452
> 0.02user 0.00system 0:00.03elapsed 72%CPU (0avgtext+0avgdata 3852maxresident)k
> 0inputs+0outputs (0major+1135minor)pagefaults 0swaps

However, from-queries take their time:

> ; time notmuch count 'not tag:replied and to:nils@dieweltistgarnichtso.net'
> 5328
> 0.10user 0.15system 0:14.14elapsed 1%CPU (0avgtext+0avgdata 3472maxresident)k
> 157544inputs+0outputs (0major+1039minor)pagefaults 0swaps

mjw1009 can reproduce if the from-query contains an "@" and thinks the
problem may be "something deeper down in notmuch (actually probably in
xapian)".


Greetings,
-- 
Nils Dagsson Moskopp // erlehmann
<http://dieweltistgarnichtso.net>