Re: Precedence of standard comparison operators

On 02/26/2015 10:56 AM, Tom Lane wrote:
> Simon Riggs <simon@2ndQuadrant.com> writes:
>> On 20 February 2015 at 20:44, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> Well, assuming that we're satisfied with just having a way to warn
>>> when the behavior changed (and not, in particular, a switch that can
>>> select old or new behavior)
>> I'm in favour of your proposed improvements, but I'm having a problem
>> thinking about random application breakage that would result.
>> Having a warn_if_screwed parameter that we disable by default won't
>> help much because if you are affected you can't change that situation.
>> There are too many applications to test all of them and not all
>> applications can be edited, even if they were tested.
> I find this argument to be unhelpful, because it could be made in exactly
> the same words against any non-backwards-compatible change whatsoever.
> Nonetheless, we do make non-backwards-compatible changes all the time.



That's true, we do. But finding out where apps are going to break is not 
going to be easy. Reviewing a million lines of code to examine where 
changes in operator precendence might affect you could be an enormous 
undertaking for many users. I understand the need, but the whole 
prospect makes me very, very nervous, TBH.

cheers

andrew