dovecot - Aug 2008 - IMAP maildir performance difference between dovecot-uidlist versions?

Hi,

Is there an IMAP performance difference using Maildir between using 
version 3 and version 1 of the dovecot-uidlist (either dovecot 1.0.7 or 
1.1.2)? It isn't entirely clear to me there is any difference as the 
filename may contain the size/vsize information. The servers will 
eventually be running 1.1.2 with the maildir_copy_preserve_filename 
turned on.

I'm doing a batch migration from courier to dovecot 1.0.7 and eventually 
dovecot 1.1.2. These servers are, and will continue to be, IMAP only 
(i.e. dedicated control/dovecot-uidlist files). The migration script is 
run once - no build on the fly. It does a readdir() to get the full 
filenames and make sure that list entries are only for existing files. 
As a result, there is almost complete freedom in the output format for 
the dovecot-uidlist.

Many thanks in advance!

---Jack

P.S. For better or worse, it does seem that once you are stuck with 
whatever initial version you choose.



-- 
Jack Stewart
IMSS, California Institute of Technology,
M/C 1-10, 1200 E. California Blvd, Pasadena, CA 91125
jstewart at caltech.edu / 626-309-4690
http://www.imss.caltech.edu

On Sun, 2008-08-17 at 12:33 -0700, Jack Stewart wrote:
> Hi,
> 
> Is there an IMAP performance difference using Maildir between using 
> version 3 and version 1 of the dovecot-uidlist (either dovecot 1.0.7 or 
> 1.1.2)?
There are two differences in version 3:

1. It's extensible, so it allows some extra metadata fields. If the file
name doesn't already contain size/vsize then it might write the sizes to
uidlist to optimize some usage patterns (pop3 mainly).

2. New data may be appended to dovecot-uidlist instead of the entire
file being recreated all the time. This will surely make the performance
better.

In any case Dovecot v1.0 will always write only v1 files while Dovecot
v1.1 will always write only v3 files, so you won't be able to choose
between them.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: This is a digitally signed message part
URL:
<http://dovecot.org/pipermail/dovecot/attachments/20080817/6714ebda/attachment-0002.bin>