On another thread [0], Alexander Lakhin pointed out, indirectly, that partitions created using LIKE+ATTACH now have different not-null constraints from partitions created using PARTITION OF.
postgres=# CREATE TABLE t (i int PRIMARY KEY) PARTITION BY RANGE (i); postgres=# CREATE TABLE t1 PARTITION OF t DEFAULT ; postgres=# \d+ t1 ... Partition of: t DEFAULT No partition constraint Indexes: "t1_pkey" PRIMARY KEY, btree (i) Access method: heap But if it's created with LIKE: postgres=# CREATE TABLE t1 (LIKE t); postgres=# ALTER TABLE t ATTACH PARTITION t1 DEFAULT ; ..one also sees: Not-null constraints: "t1_i_not_null" NOT NULL "i" It looks like ATTACH may have an issue with constraints implied by pkey. [0] https://www.postgresql.org/message-id/8034d1c6-5f0e-e858-9af9-45d5e246515e%40gmail.com -- Justin