On Fri, Mar 4, 2016 at 7:27 PM, Robert Haas <robertmh...@gmail.com> wrote:
> On Thu, Mar 3, 2016 at 2:48 AM, Shulgin, Oleksandr > <oleksandr.shul...@zalando.de> wrote: > > On Wed, Mar 2, 2016 at 7:33 PM, Alvaro Herrera <alvhe...@2ndquadrant.com > > > > wrote: > >> Shulgin, Oleksandr wrote: > >> > >> > Alright. I'm attaching the latest version of this patch split in two > >> > parts: the first one is NULLs-related bugfix and the second is the > >> > "improvement" part, which applies on top of the first one. > >> > >> So is this null-related bugfix supposed to be backpatched? (I assume > >> it's not because it's very likely to change existing plans). > > > > For the good, because cardinality estimations will be more accurate in > these > > cases, so yes I would expect it to be back-patchable. > > -1. I think the cost of changing existing query plans in back > branches is too high. The people who get a better plan never thank > us, but the people who (by bad luck) get a worse plan always complain. > They might get that different plan when they upgrade to the latest major version anyway. Is it set somewhere that minor version upgrades should never affect the planner? I doubt so. -- Alex
