On Fri, Mar 31, 2023 at 9:07 AM Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
Siddharth Jain <siddhsql@xxxxxxxxx> writes:
> I think the two are equivalent. If not, could you please explain why?
Well, they're formally equivalent if you require there to be only one
X value per partition (ie, PARTITION BY LIST with only one listed value
per partition); if there's more, they're not the same thing.
Yes. This is what I have. I think I understand now. Is following correct?
when a PK is created on (X,Y) on the parent table what happens internally is that the command is run individually on each of the child tables. nothing more. nothing less.
Neither one guarantees that Y is globally unique. We have no mechanism
for enforcing uniqueness across partitions except for partition key
columns.
regards, tom lane
