Re: Question on creating keys on partitioned tables

Thanks Laurenz.

I think the two are equivalent. If not, could you please explain why?

On Fri, Mar 31, 2023 at 6:46 AM Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at>
wrote:

> 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.
>
> Yours,
> Laurenz Albe
>