> On Aug 2, 2016, at 2:33 AM, Geoff Winkless <pgsqlad...@geoff.dj> wrote:
>> On 2 August 2016 at 08:11, Alfred Perlstein <alf...@freebsd.org> wrote:
>>> On 7/2/16 4:39 AM, Geoff Winkless wrote:
>>> I maintain that this is a nonsense argument. Especially since (as you 
>>> pointed out and as I missed first time around) the bug actually occurred at 
>>> different records on different slaves, so he invalidates his own point.
>> Seriously?
> No, I make a habit of spouting off random arguments to a list full of
> people whose opinions I massively respect purely for kicks. What do
> you think?
>> There's a valid point here, you're sending over commands at the block level, 
>> effectively "write to disk at this location" versus "update this record 
>> based on PK", obviously this has some drawbacks that are reason for concern.
> Writing values directly into file offsets is only problematic if
> something else has failed that has caused the file to be an inexact
> copy. If a different bug occurred that caused the primary key to be
> corrupted on the slave (or indeed the master), PK-based updates would
> exhibit similar propagation errors.
> To reiterate my point, uber's described problem came about because of
> a bug. Every software has bugs at some point in its life, to pretend
> otherwise is simply naive. I'm not trying to excuse the bug, or to
> belittle the impact that such a bug has on data integrity or on uber
> or indeed on the reputation of PostgreSQL. While I'm prepared to
> accept (because I have a job that requires I spend time on things
> other than digging through obscure reddits and mailing lists to
> understand more fully the exact cause) that in _this particular
> instance_ the bug was propagated because of the replication mechanism
> (although I'm still dubious about that, as per my comment above), that
> does _not_ preclude other bugs propagating in a statement-based
> replication. That's what I said is a nonsense argument, and no-one has
> yet explained in what way that's incorrect.
> Geoff


You are quite technical, my feeling is that you will understand it, however it 
will need to be a self learned lesson. 


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