On 07/16/2018 07:21 PM, Tom Lane wrote:
Robert Haas <robertmh...@gmail.com> writes:
I agree. As a general statement, I think the idea of trying to
prevent transactions from aborting is really scary. It's almost an
axiom of the system that we're always allowed to abort, and I think
there could be a lot of unintended and difficult-to-fix consequences
of undermining that guarantee. I think it will be very difficult to
create a sound system for delaying transactions, and I doubt very much
that the proposed system is sound.
Ugh, is this patch really dependent on such a thing?
Unfortunately it does :-( Without it the decoding (or output plugins)
may see catalogs broken in various ways - the catalog records may get
vacuumed, HOT chains are broken, ... There were attempts to change that
part, but that seems an order of magnitude more invasive than this.
TBH, I think the odds of making that work are indistinguishable from zero;
and even if you managed to commit something that did work at the instant
you committed it, the odds that it would stay working in the face of later
system changes are exactly zero. I would reject this idea out of hand.
Why? How is this significantly different from other patches touching
ProcArray and related bits?
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
