Re: BUG #12330: ACID is broken for unique constraints

Kevin Grittner <kgrittn@ymail.com> writes:
> Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Yes.  This will deliver a less meaningful error code,

> That depends entirely on whether you care more about whether the
> problem was created by a concurrent transaction or exactly how that
> concurrent transaction created the problem.

Just for starters, a 40XXX error report will fail to provide the
duplicated key's value.  This will be a functional regression,
on top of breaking existing code.

I think an appropriate response to these complaints is to fix the
documentation to point out that duplicate-key violations may also
be worthy of retries.  (I sort of thought it did already, actually,
but I see no mention of the issue in chapter 13.)
        regards, tom lane