[Dovecot] Difference between Indexing and Rescan in FTS

[Fred Kilbourn]

> -----Original Message-----
> From: dovecot-bounces at dovecot.org [mailto:dovecot-bounces at dovecot.org]
> On Behalf Of Timo Sirainen
> Sent: Tuesday, October 16, 2012 10:16 PM
> To: Fred Kilbourn
> Cc: dovecot at dovecot.org
> Subject: Re: [Dovecot] Difference between Indexing and Rescan in FTS
> 
> On 17.10.2012, at 2.14, Fred Kilbourn wrote:
> 
> > I've had squat running on dovecot 2.0 and have been updating all users
> > mailbox indexes nighty via cron with this command:
> >
> > doveadm -v search -A text xyzzyx
> 
> doveadm index is a bit more efficient.
> 
> > I've just updated to 2.1 and I'm migrating to lucene indexes, but
> reading
> > the documentation I'm having a hard time understanding the semantic
> > differences between indexing and rescanning.
> 
> doveadm fts rescan makes sure that 1) all of the old messages are
> indexed and 2) there are no extra (already deleted) messages indexed. So
> it's basically repairing fts index. You probably shouldn't run it
> automatically, or at least not very often.

Okay, you've clarified that for me.

I understand that rescan isn't a nightly task, but could be run every now
and then periodically.  How often might be appropriate if I wanted to do
this as a maintenance task?  Once a month?

Lastly, I'm trying to use the index command instead of the search command,
but I can't figure out how to make it index every mailbox for every user.
Is there a wildcard that can be used for the mailbox?  Or do I need to
iterate all the mailboxes with one command and run index however many times
for each inbox?

Thanks for your help