On Fri, 2020-06-19 at 12:12 +0530, Srinivasa T N wrote: > On Fri, Jun 19, 2020 at 11:44 AM David Rowley <dgrowleyml@gmail.com> wrote: > > On Fri, 19 Jun 2020 at 17:42, Srinivasa T N <seenutn@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? > > > > 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?
In the case of "integer", the hash function is "pg_catalog"."hashint4".