On 2019-Jan-04, Michael Paquier wrote:
> That should not be allowed to commit directly. I think that we should
> just add a new value for MyXactFlags which tracks the transaction
> where the temporary namespace has been created, and generate an error
> if trying to use 2PC in this case.
That implies that a 2PC transaction will fail if it's run in a session
for which the temp namespace doesn't previously exist. I think it's a
fairly ugly failure mode, and one that normal testing will not catch
because it'll occur very rarely. An app that detects this problem at
run time will have to create a random temp object, commit normally, then
re-run the 2PC transaction from the start ... a lot of code to deal with
something that shouldn't happen in the first place.
I wonder if we can somehow create the temp schema in a way that makes it
immediately visible to everyone, and not depend on the commit status of
the creating transaction -- say mark the tuple with xmin=frozenXid or
something like ugly that.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
