[DB-SIG] Two-phase commit API proposal (was Re: Any standard for two phase commit APIs?)

[Dieter Maurer]

James Henstridge wrote at 2008-1-22 20:33 +0900:
> ...
>I do see a use for the branch qualifier though.  In a distributed
>transaction, each resource should have a different transaction ID

Why?
Why is it not equally good to use a common transaction id for
all resource managers?

>that
>share a common global transaction ID but separate branch qualifiers.
>
>As transaction IDs are global within database clusters for some
>backends (PostgreSQL, MySQL and probably others), the branch qualifier
>is necessary if two databases from the cluster are used in the global
>transaction.

They refer to the same transaction -- even when several databases
in a cluster are affected.

The transaction as a whole will want to get prepared, committed, rolledback...



-- 
Dieter