On Thu, Dec 11, 2014 at 10:43 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> Version 1.0 of INSERT ... ON CONFLICT UPDATE was posted in August -
>> when development launched. It still doesn't have a reviewer, and it
>> isn't actually in evidence that someone else has so much as downloaded
>> and applied the patch
> I'm not sure whether that patch is going to go anywhere. There has
> been so much arguing about different aspects of the design that felt
> rather unproductive that I think most of the people who would be
> qualified to commit it have grown a bit gun-shy. That would be a good
> problem to get fixed, but I don't have a proposal.
Really?
I have acted comprehensively on 100% of feedback to date on the
semantics/syntax of the ON CONFLICT UPDATE patch. The record reflects
that. I don't believe that the problem is that people are gun shy. We
haven't even had a real disagreement since last year, and last year's
discussion of value locking was genuinely very useful (I hate to say
it, but the foreign key locking patch might have considered the
possibility of "unprincipled deadlocks" more closely, as we saw
recently).
Lots of other systems have a comparable feature. Most recently, VoltDB
added a custom "UPSERT", even though they don't have half the SQL
features we do. It's a complicated feature, but it's not a
particularly complicated feature as big, impactful features go (like
LATERAL, or logical decoding, or the foreign key locking stuff). It's
entirely possible to get the feature in in the next few months, if
someone will work with me on it.
Even Heikki, who worked on this with me far more than everyone else,
found the value locking page a useful summary. He didn't even know
that there was a third design advocated by Simon and Andres until he
saw it! The discussion was difficult, but had a useful outcome,
because accounting for "unprincipled deadlocks" is a major source of
complexity. I have seen a lot of benefit from comprehensively
documenting stuff in one place (the wiki pages), but that has tapered
off.
--
Peter Geoghegan