Re: XA Xid to PostgreSQL transaction ID

On Thu, 14 Oct 2010, Daniele Varrazzo wrote:

> I have implemented two-phase commit into the Python PostgreSQL driver
> psycopg2. As the Python DBAPI is XA inspired, the transaction IDs it
> demands to handle are composed by triples (format_id, gtrid, bqual).
> PostgreSQL instead asks for plain strings as transaction IDs.
>
> I'd like to implement the mapping algorithm exactly the way the JDBC
> driver does, as it would allow tools written in Python to interoperate
> to ones written in Java and understand each other the XA components of
> the transaction IDs.
>

I'm not sure how valuable that will really be. This information should
really only be useful to a transaction manager(TM), so I'm not sure what
interoperability would gain. No TM is going to start a Java transaction
and later try to recover it using a Python client (or the other way
around).

> As a test I have in the test suite the triple (42, 'gtrid', 'bqual')
> is converted into the string '42_Z3RyaWQ=_YnF1YWw=': I'd like to know,
> if possible, if this is the same result obtained by the JDBC driver.
> Alternatively, if you can provide me one or more known triple ->
> string transformation examples, I can check them and add them to the
> test suite.

Yes, this is the same result as the JDBC driver.

Kris Jurka