Re: tab completion for prepared transactions?

On Sun, 2010-01-24 at 19:29 +0200, Heikki Linnakangas wrote:
> Peter Eisentraut wrote:
> > On lör, 2010-01-23 at 12:42 -0500, Tom Lane wrote:
> >> Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> >>> Was there a designed-in reason not to have psql tab completion for
> >>> COMMIT/ROLLBACK PREPARED ...? It does complete the "PREPARED" but not
> >>> the transaction identifiers. Maybe it's not a common use case, but
> >>> these transaction identifiers sure can be nontrivial to type.
> >> Hmm, what's the use scenario? I would think that painfully long
> >> gxids would come from some XA manager software, which would be
> >> responsible for committing or canceling them. Manual override
> >> of that would usually be a bad idea.
>
> Right, I vaguely recall that the idea of tab-completion for those
> commands was rejected when 2PC was added because of that. A user sitting
> at a psql terminal is not supposed to prepare a transaction. That's
> application server's business.

Maybe so, but that doesn't actually stop people doing it.

I would like a mechanism in the server to prevent a session from
accepting anything other than COMMIT or ROLLBACK PREPARED after a
PREPARE. Otherwise it's possible to screw up your prepared xact and
leave it hanging there.

--
Simon Riggs www.2ndQuadrant.com