On Tue, Jan 6, 2015 at 12:29 PM, Amit Langote <langote_amit...@lab.ntt.co.jp > wrote:
> On 06-01-2015 PM 04:00, Ashutosh Bapat wrote: > > On Tue, Jan 6, 2015 at 12:23 PM, Atri Sharma <atri.j...@gmail.com> > wrote: > >>> We can eliminate the new node and put onus or having the right order on > >>> the user like we do with volatile setting of the function. > >>> > >>> > >> > >> That is exactly what the new node does, since we are not re sorting > right > >> now in case the order is wrong. Please see my explanation upthread, > >> OrderCheck node's primary purpose is to check for a user error in the > >> result rows order. The onus right now to give correct order is on user. > >> > >> > > Even checking whether the output of the function is in the right order or > > not, has its cost. I am suggesting that we can eliminate this cost as > well. > > For example, PostgreSQL does not check whether a function is really > > immutable or not. > > > > Sounds something like ORDERED BY x implying output is "known" ordered by > x perhaps enough hint for the planner to make necessary plan choices > though I may be wrong. > > > I may be missing something, but isnt what you mentioned the exact functionality this patch adds?
