Tom Lane wrote:
> I don't see a "substantial additional burden" there. What I would
> imagine is needed is that the slave transmits a single number back
> --- its current oldest xmin --- and the walsender process publishes
> that number as its transaction xmin in its PGPROC entry on the master.
>
That is exactly the core idea I was trying to suggest in my rambling
message. Just that small additional bit of information transmitted and
published to the master via that route, and it's possible to optimize
this problem in a way not available now. And it's a way that I believe
will feel more natural to some users who may not be well served by any
of the existing tuning possibilities.
--
Greg Smith 2ndQuadrant US Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com www.2ndQuadrant.us