On Thu, 2023-03-30 at 17:05 -0700, Siddharth Jain wrote: > I have this question. Say I create a partitioned table on column X. > > Option 1: > > I add a primary key on (X,Y). Y is another column. Even though Y is a globally unique PK (global meaning it is unique across partitions, not just in one partition), Postgres does not allow me to > create a PK on Y in a partitioned table. > > Option 2: > > I add PK on Y on each of the partitions > > Are these not equivalent? If not, which is better and why?
No, they are not equivalent.
Option 2 comes closer to guaranteeing uniqueness for column X, so use that.
> PS: This is what my best friend had to say: > > [...] If you are using the "table inheritance" approach [...]
Don't even consider that. Declarative partitioning is so much better.