"Marko Kreen" <markokr at gmail.com> writes:
> On 10/1/07, Tom Lane <tgl at sss.pgh.pa.us> wrote:
>> I'm having quite a bit of a problem with the above.  Why is
>> InvalidTransactionId mapped to MAX_TXID, which presumably is part of the
>> normal XID rotation and hence only larger than half of the universe,
>> when the other special XIDs map as themselves?

> Because InvalidTransactionId is supposed to be always invisible,
> but others always visible?  And we don't want to add epoch to
> any of them.

Well, all three of the "special" xids need to be epoch-independent.
I still think this is either bad design or an outright bug.

> I used StringInfo as it was only buffer tool available from backend...

Maybe, but don't be too surprised if it breaks under you ...

			regards, tom lane