> 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
Geoff, You are quite technical, my feeling is that you will understand it, however it will need to be a self learned lesson. -Alfred -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
