[Dovecot] No speed improvement with FTS for iOS 7?

[Nicholas Riley]

Hi,

I recompiled Dovecot with Lucene FTS to try to improve iOS 7 IMAP search 
speed.

Unfortunately this does not seem to help.

I have 60 mailboxes, totaling 300 MB; lucene-indexes is 30 MB in size.

% doveadm mailbox status -t all '*'
messages=16335 recent=0 unseen=1736 vsize=280049586

Searching for a single word which is present in two messages of one 
mailbox takes 40 seconds to return.  This is true whether or not fts is 
enabled.

doveadm search takes much less than 1 second to do the same search.

% time doveadm search BODY cython
d8f09230c97af952b60c0000c1443b93 1
d8f09230c97af952b60c0000c1443b93 2
doveadm search BODY cython  0.18s user 0.05s system 99% cpu 0.230 total

With fts disabled, it takes about 6.5 seconds.  This is still a long way 
from 40 seconds.

Is there any way I can make dovecot perform better here?

Thanks,
-- 
Nicholas Riley <njriley at illinois.edu>