[Cosmo-dev] Re: [service-dev] Deployment of Cosmo persistence load distribution

[Brian Moseley]

On 7/19/06, Jared Rhine <jared at wordzoo.com> wrote:

> Ok, so given multi-database distribution is well-handled by JTA, how does
> JTA work into the product architecture?  I doubt it's in the mix now, but
> are there any nails sticking out where JTA might be the hammer?

not that i can think of. theoretically we could design a feature where
cosmo has to perform a transaction across multiple databases, but i
haven't imagined that feature yet.

> Does JTA provide components for the "database lookup service" we hypothesize
> we need?  Maybe magic behind the scenes to do the partitioning of physical
> data for you?  Hope beyond hope, provide a mechanism to query across
> databases (as Brian confirms needs to be worked out for share searching,
> acls, "etc".)

no, jta works against jdbc connections, iirc, and it only deals with
writes to multiple connections within a transaction, not merging
queries across multiple connections. there may be other tools out
there that help with this problem though. for instance, i could
imagine maintaining a cached index of key info from the databases that
would help us follow references between the databases.