Re: WIP: Detecting SSI conflicts before reporting constraint violations

On Fri, Mar 11, 2016 at 8:50 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> On 3 February 2016 at 23:12, Thomas Munro <thomas.munro@enterprisedb.com>
> wrote:
>
>>
>>  It quacks suspiciously like a bug.
>
>
> Agreed
>
> What's more important is that is very publicly a bug in the eyes of others
> and should be fixed and backpatched soon.
>
> We have a maintenance release coming in a couple of weeks and I'd like to
> see this in there.

As I understand it, the approach I've taken here can't be backpatched
because it changes the aminsert_function interface (it needs the
current snapshot when inserting), so I was proposing this as an
improvement for 9.6.  I guess there are other way to get the right
snapshot into btinsert (and thence _bt_check_unique), but I didn't
think it would be very classy to introduce a 'current snapshot' global
variable to smuggle it in.