Re: Commit turns into rollback?

Am Freitag, 17. März 2006 16:07 schrieb Tom Lane:
> It would also move us further away from the SQL standard.  The spec says
> that COMMIT ends the transaction, full stop, not "ends it only if you're
> not in an error state".  Of course the spec hasn't got a notion of a
> transaction error state at all, but my point is that making COMMIT leave
> you in the broken transaction is not an improvement compliance-wise.

The standard does address the issue of transactions that cannot be committed 
because of an error.  In 16.6. <commit statement> GR 6 it basically says that 
if the transaction cannot be completed (here: because of a constraint 
violation), then an exception condition should be raised.  That is, the 
transaction is over but you get an error.  I think that behavior would be 
better.  For example, Java programs will get an exception and know something 
is wrong.  Right now, I don't even know whether it is possible in all 
programming interfaces to get at the command tag and infer failure to commit 
from there.
-- 
Peter Eisentraut
http://developer.postgresql.org/~petere/