Peter Geoghegan <pg@heroku.com> writes:
> On Fri, Sep 12, 2014 at 11:09 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I'm confused. Are you proposing to return to sort + de-dup of JSON
>> arrays? Surely that is completely broken. Arrays are ordered.
> Sorry, my earlier remarks were premature. In fact, that alteration
> only applied to existence, not containment. However, arrays are
> ordered for the purposes of equality, but not containment.
My remarks were also premature, because looking back at the referenced
commit, I see what it removed was a sort and de-dup as a preliminary step
in containment comparisons, not as a generic alteration of array contents.
So that was sane enough, though I concur with Heikki's opinion that it
likely failed to be a performance win.
regards, tom lane
