Nikita Glukhov <n.glu...@postgrespro.ru> writes: > On 20.09.2017 23:19, Alexander Korotkov wrote: >> On Wed, Sep 20, 2017 at 11:07 PM, Tom Lane <t...@sss.pgh.pa.us >> <mailto:t...@sss.pgh.pa.us>> wrote: >>> Maybe I'm missing something, but it appears to me that it's >>> impossible for bbox->low.x to be NaN unless circle->center.x and/or >>> circle->radius is a NaN, in which case bbox->high.x would also have been >>> computed as a NaN, >>> making the swap entirely useless.
> It is possible for bbox->low.x to be NaN when circle->center.x is and > circle->radius are both +Infinity. Without this float-order-preserving > swapping > one regression test for KNN with ORDER BY index will be totally broken > (you can > try it: https://github.com/glukhovn/postgres/tree/knn). If that's the reasoning, not having a comment explaining it is inexcusable. Do you really think people will understand what the code is doing? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
