>>>>> "Rajkumar" == Rajkumar Raghuwanshi >>>>> <rajkumar.raghuwan...@enterprisedb.com> writes:
Rajkumar> Hi Rajkumar> ntile() throws ERROR when hashagg is false, test case given Rajkumar> below. Rajkumar> postgres=# create table foo (a int, b int, c text); Rajkumar> CREATE TABLE Rajkumar> postgres=# insert into foo select i%20, i%30, to_char(i%12, 'FM0000') from Rajkumar> generate_series(0, 36) i; Rajkumar> INSERT 0 37 Rajkumar> postgres=# explain select ntile(a) OVER () from foo GROUP BY a; This query isn't actually legal per the spec; the argument of ntile is restricted to being a constant or parameter, so it can't change from row to row. PG is more flexible, but that doesn't make the query any more meaningful. What I think pg is actually doing is taking the value of the ntile() argument from the first row and using that for the whole partition. In your example, enabling or disabling hashagg changes the order of the input rows for the window function (since you've specified no ordering in the window definition), and with hashagg off, you get the smallest value of a first (which is 0 and thus an error). -- Andrew (irc:RhodiumToad)
