30.04.2024 03:10, Dmitry Koval wrote:
Hi!
1.
29.04.2024 21:00, Alexander Lakhin wrote:
I still wonder, why that constraint (now with a less questionable name) is
created during MERGE?
The SPLIT/MERGE PARTITION(S) commands for creating partitions reuse the existing code of CREATE TABLE .. LIKE ...
command. A new partition was created with the name "merge-16385-26BCB0-tmp" (since there was an old partition with the
same name). The constraint "merge-16385-26BCB0-tmp_i_not_null" was created too together with the partition.
Subsequently, the table was renamed, but the constraint was not.
Now a new partition is immediately created with the correct name (the old
partition is renamed).
Maybe I'm doing something wrong, but the following script:
CREATE TABLE t (i int, PRIMARY KEY(i)) PARTITION BY RANGE (i);
CREATE TABLE tp_0 PARTITION OF t FOR VALUES FROM (0) TO (1);
CREATE TABLE tp_1 PARTITION OF t FOR VALUES FROM (1) TO (2);
CREATE TABLE t2 (LIKE t INCLUDING ALL);
CREATE TABLE tp2 (LIKE tp_0 INCLUDING ALL);
creates tables t2, tp2 without not-null constraints.
But after
ALTER TABLE t MERGE PARTITIONS (tp_0, tp_1) INTO tp_0;
I see:
\d+ tp_0
...
Indexes:
"tp_0_pkey" PRIMARY KEY, btree (i)
Not-null constraints:
"tp_0_i_not_null" NOT NULL "i"
Best regards,
Alexander
