On 02.03.2017 11:41, Robert Haas wrote:
Sounds generally good. One thing to keep in mind is that - in this system - a UNIQUE index on the parent doesn't actually guarantee uniqueness across the whole partitioning hierarchy unless it so happens that the index columns or expressions are the same as the partitioning columns or expressions. That's a little a counterintuitive, and people have already been complaining that a partitioned table + partitions doesn't look enough like a plain table. However, I'm not sure there's a better alternative, because somebody might want partition-wise unique indexes even though that doesn't guarantee global uniqueness. So I think if someday we have global indexes, then we can plan to use some other syntax for that, like CREATE GLOBAL [ UNIQUE ] INDEX.
Yes, I absolutely agree with your message that cross-partition uniqueness is guaranteed through global index on partitioned table apart from the case when the index key are the same as partitioning key (or index comprises partitioning key in general).
Thanks for your comment. I'll try to propose the first patches as soon as possible.
-- Maksim Milyutin Postgres Professional: http://www.postgrespro.com Russian Postgres Company -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers