[Dovecot] Using MySQL to store email?

[Marc Perkel]

Steffen Kaiser wrote:
> On Tue, 6 Jun 2006, nodata wrote:
>
>>> Seems to me that MySQL could somplify all the backend stuff
>
> There are different SQL-Servers out there, e.g. Postgres.
>
>> Putting everything in a database would provide one benefit:
>> * Less storage space needed due to duplicated e-mail
>
> Don't know, if such stuff will work out-of-the-box, but if the mails 
> is broken into headers and bodies (for the message awhole and each 
> MIME part), it can be very beneficial.
>
>> NOT putting everything in a database provides plays to Linux's 
>> strengths:
>> everything is a file, meaning we can use all of the standard 
>> file-focused
>
> And limits. Why does Dovecot has so many options for locking? ;-) What 
> are the files days old in the tmp/ folders?
>
>> text processing tools. If everything is a file, backups and restores 
>> are a
>> piece of cake.
>
> Well, the problem with a file-based database (Dovecot's indexes etc. 
> are in fact a database) is that you must use the same locking and/or 
> terminate / suspend the service, otherwise there is the possibility 
> that the data and the indexes are out-of-sync. The transactions of a 
> full-featured DB will make backups and restores reliable, however, 
> partial restores won't be possible without a good toolset. Do you know 
> the spot of time _for_ _sure_ Dovecot has committed all internally 
> cached data into the index- or control files?
>
> Moving away from the filesystem will introduce other problems, e.g. 
> one needs to introduce a full ACL implementation. And no operation can 
> be easily performed in a DB manually, as you can with files. However, 
> for the Dovecot files (e.g. keywords of a message) you need a toolset 
> even today. For a SQL-Server, you need to know the structure and you 
> can built a toolset with any language you like.
>
> I'm neither advocating filesystem- nor DB-based mail storage, both has 
> there strength and weakness. But I'd expect that you can rely on the 
> DB's strangth for indexing and storing data well and you can focus on 
> the processing of mails.
>
> BTW: Cyrus uses a DB, doesn't it?
>
>

I'm suggesting it in addition to MBOX and MAILDIR. And of course if 
there's a MySQL version then other databases will follow. Just seems to 
me that if I were running a really BIG email operation that MySQL could 
have some serious benefits.