Re: age(xid) on hot standby - Mailing list pgsql-hackers

Alvaro Herrera <alvherre@commandprompt.com> writes:
> Excerpts from Peter Eisentraut's message of mié dic 28 15:04:09 -0300 2011:
>> On a hot standby, this fails with:
>> ERROR:  cannot assign TransactionIds during recovery

> I think we could just have the xid_age call
> GetCurrentTransactionIdIfAny, and if that returns InvalidXid, use
> ReadNewTransactionId instead.  That xid_age assigns a transaction seems
> more of an accident than really intended.

The trouble with using ReadNewTransactionId is that it makes the results
volatile, not stable as the function is declared to be.
        regards, tom lane