On Fri, Jun 19, 2020 at 11:44 AM David Rowley <dgrowle...@gmail.com> wrote:
> On Fri, 19 Jun 2020 at 17:42, Srinivasa T N <seen...@gmail.com> wrote: > > After seeing the below, I feel partitioning is not working properly > or it maybe case that my understanding is wrong. Can somebody explain me > what is happening? > > > postgres=# select * from busbar_version6; > > objectid | ver_id > > ----------+-------- > > (0 rows) > > > > postgres=# select * from busbar_version7; > > objectid | ver_id > > ----------+-------- > > 6 | 6 > > (1 row) > > > > Why second insert has gone to table busbar_version7 instead of > busbar_version6? > > It's your understanding that's not correct. The value of is passed > through a hash function and the partition is selected based partition > matching the remainder value after dividing the return value of the > hash function by the largest modulus of any partition. > > That might surprise you, but how would you select which partition a > varchar value should go into if you didn't use a hash function. > > David > How can I see the output of hash function that is used internally? Regards, Seenu.
