Re: Oracle: Java + distributed transactions (CORBA OTS + 2PC)

On Sun, 22 Aug 1999, Klaus Hildner wrote:

> Hello world,
>
> is there anybody out there who can give me a hint on how to drive an
> Oracle server from a Java program; I do not need the usual JDBC
> query/update functionality but the possibility to drive an XA-like
> two-phase commit (2PC) protocol.
>
> I am currently working on my diploma thesis and have developed a
> skeleton manufacturing execution system MES with Java (JBuilder) and
> CORBA (VisiBroker). Currently, the resource part is simulated in memory,
> but it takes part in transaction completion via the OTS-coordinator's
> prepare(), commit(), commit_one_phase(), and rollback() methods.

I'm afraid that I don't understand a lot of this. I haven't used JDBC, and I'm not familiar with manufacturing execution systems. Aren't all resources "simulated in memory"? Do you mean that you aren't actually driving any underlying resource, just simulating its participation in the transaction? If so, then that shouldn't matter.

Hopefully, if you phrase your question in terms of the OTS interface, then people here will be able to help you without necessarily understanding the details of your application.

> Important for me is a mechanism that lets a resource alternatingly join
> several transaction branches, i. e. the resource should work on part of
> one transaction, then on part of another, and some time later commit the
> first one and some time later maybe rollback the second one.

Strictly speaking, this is a non-sensical wish:

	"Each object supporting the _Resource_ interface is implicitly
	associated with a single top-level transaction." (CosTransactions,
	10.3.7, from an old version but this part, I'm pretty sure,
	is the same in the latest version.)

> This could
> be done by connection pooling and JDBC, I think. But it is a problem to
> get the prepare() functionality for the 2PC which is very important for
> consistent, distributed updates.

I'm afraid that all of this is greek to me. Resources are associated with at most a single transaction, and so I really don't understand your requirement here.

> Anyone having any hints, program examples, anything?

I'd need to understand better what you're trying to accomplish before being able to help you.

--

Todd Graham Lewis                        Postmaster, MindSpring Enterprises
tlewis_at_mindspring.net                                (800) 719-4664, x22804

      "Do not squander time.  That is the stuff that life is made of."