I got another idea: whenever I set a property as unique it is usually only
one and also that property serves as the natural id of the saga, for
example a customer id or invoice id. Also, almost all messages are mapped
to that particular id instead of the saga id. So, since RavenDB supports
any kind of string as id, why not use that property as the actual document
id? The saga id in this case is usually never used and if it were used
anyway (in a ISagaMessage) it can be queried using a lucene index. Since
the saga id is a guid and guaranteed to be unique the persister don't even
need to validate it's uniqueness.

So, what we need is a [Key] attribute instead of a [Unique]. The default
behavior will still be to use the saga id as document id. But if there is
one (and only one) property with a [Key] attribute this property will be
the document id instead.

This way we can use Raven:s id-handling to our advantage instead of trying
to gain uniqueness in ways that Raven wasn't designed to handle.

What do you think? If you like this I can probably scoop up a proof on
concept to see if it works...

/Johannes

2012/1/14 Andreas hlund <
reply@reply.github.com
>

> Yes, lets go with that!
>
> On Fri, Jan 13, 2012 at 11:22 PM, Johannes Gustafsson <
> reply@reply.github.com
> > wrote:
>
> > NH supports multiple attributes. In NH:s case it's really simple, it just
> > adds a unique constraint for every column marked as unique.
> >
> > Although I have been thinking of use cases with multiple unique
> properties,
> > I don't have a problem supporting only one. On the other hand, I see no
> > real reason for the core to restrict it just because some saga persisters
> > cant support it.
> >
> > How about letting each saga persister implementation decide? Maybe some
> > implementations simply cant support unique properties. In that case, just
> > let them throw an exception during startup if someone tries to do it
> > anyway.
> >
> >
> >
> > 2012/1/13 Andreas hlund <
> > reply@reply.github.com
> > >
> >
> > > Johannes: Is the NH saga persister supporting multiple [Unique]
> > attributes?
> > >
> > > All: Given that its very rare to need multiple unique properties.
> Should
> > we
> > > restrict users to only support one. This makes it easier to implement
> new
> > > saga storage's. Users needing more than one should can be guided to set
> > > their own constraints in manually?
> > >
> > > On Fri, Jan 13, 2012 at 2:32 AM, Jonathan Matheus <
> > > reply@reply.github.com
> > > > wrote:
> > >
> > > > No, I was saying that we can use session.Delete. We can also support
> > > > multiple properties pretty easily. I can do both tomorrow
> > > >
> > > >
> > > >
> > > > On Jan 12, 2012, at 3:51 PM, Andreas hlund<reply@reply.github.com>
> > > wrote:
> > > >
> > > > > So you're saying that we can support multiple unique properties?
> > > > >
> > > > > On Thu, Jan 12, 2012 at 6:18 PM, Jonathan Matheus <
> > > > > reply@reply.github.com
> > > > >> wrote:
> > > > >
> > > > >> We can now that we're using a UOW. We previously opted not to rely
> > on
> > > > >> Raven change tracking, but recently changed our minds. I'll change
> > it.
> > > > >>
> > > > >> ---
> > > > >> Reply to this email directly or view it on GitHub:
> > > > >>
> > > > >>
> > > >
> > >
> >
> https://github.com/NServiceBus/NServiceBus/commit/44f79a38a54aebfcfe7d3bc070fd90cce523b884#commitcomment-861627
> > > > >>
> > > > >
> > > > > ---
> > > > > Reply to this email directly or view it on GitHub:
> > > > >
> > > >
> > >
> >
> https://github.com/NServiceBus/NServiceBus/commit/44f79a38a54aebfcfe7d3bc070fd90cce523b884#commitcomment-862610
> > > >
> > > > ---
> > > > Reply to this email directly or view it on GitHub:
> > > >
> > > >
> > >
> >
> https://github.com/NServiceBus/NServiceBus/commit/44f79a38a54aebfcfe7d3bc070fd90cce523b884#commitcomment-863209
> > > >
> > >
> > > ---
> > > Reply to this email directly or view it on GitHub:
> > >
> > >
> >
> https://github.com/NServiceBus/NServiceBus/commit/44f79a38a54aebfcfe7d3bc070fd90cce523b884#commitcomment-865707
> > >
> >
> > ---
> > Reply to this email directly or view it on GitHub:
> >
> >
> https://github.com/NServiceBus/NServiceBus/commit/44f79a38a54aebfcfe7d3bc070fd90cce523b884#commitcomment-866345
> >
>
> ---
> Reply to this email directly or view it on GitHub:
>
> https://github.com/NServiceBus/NServiceBus/commit/44f79a38a54aebfcfe7d3bc070fd90cce523b884#commitcomment-866478
>