Re: [HACKERS] logical decoding of two-phase transactions

On 17 March 2017 at 23:59, Robert Haas <robertmhaas@gmail.com> wrote:

> But that lock could need to be held for an unbounded period of time -
> as long as decoding takes to complete - which seems pretty
> undesirable.

Yeah. We could use a recovery-conflict like mechanism to signal the
decoding session that someone wants to abort the xact, but it gets
messy.

>  Worse still, the same problem will arise if you
> eventually want to start decoding ordinary, non-2PC transactions that
> haven't committed yet, which I think is something we definitely want
> to do eventually; the current handling of bulk loads or bulk updates
> leads to significant latency.

Yeah. If it weren't for that, I'd probably still just pursue locking.
But you're right that we'll have to solve this sooner or later. I'll
admit I hoped for later.

-- Craig Ringer                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services