Re: XA support - Mailing list pgsql-jdbc

From Heikki Linnakangas
Subject Re: XA support
Date
Msg-id Pine.OSF.4.61.0506302112310.45052@kosh.hut.fi
Whole thread Raw
In response to Re: XA support  (Scott Marlowe <smarlowe@g2switchworks.com>)
Responses Re: XA support  (Scott Marlowe <smarlowe@g2switchworks.com>)
List pgsql-jdbc
On Wed, 29 Jun 2005, Scott Marlowe wrote:

> On Wed, 2005-06-29 at 15:27, Dave Cramer wrote:
>> I see option A below as the lesser of three evils. Is it reasonable
>> to believe that people using XA would
>> know enough to allocate enough connections ?
>>
>> Optionally we could have two implementations and choose between A and B
>
> If they've used it before with jdbc, yes.  It's the way Oracle does it
> too.  Under Jboss you have a two to one ration of backend to frontend
> connections. I.e. every application connection going through an XA
> connector requires TWO backend connections.

Do you mean that Oracle opens extra connections behind the scenes? That's
not what I saw happening. I ran ethereal while running the test case, and
it showed just one TCP connection and all SQL statements flowing through
that.

I'm no Oracle expert though. Maybe it opens multiple virtual connections
that are multiplexed into one TCP connection, I don't know.

That JBoss thing is quite interesting too. I wonder why they do that.

> IT might be worth putting a note in the jdbc docs though.

Definitely.

- Heikki

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