Kirill Reshke <[email protected]> 于2026年5月13日周三 13:08写道：
> On Wed, 13 May 2026 at 09:39, Chao Li <[email protected]> wrote: > > > > Hi, > > > > While testing ALTER TABLE ... SPLIT PARTITION, I found a bug and a few > behaviors and messages that seem worth improving. > > > > 0. A bound-overlap bug > > > > I numbered this item as 0 because I found it after finishing items 1, 2, > and 3. While doing a final verification before sending this email, I was > surprised to find that the partitioned table ended up with two overlapping > partitions. > > > > Here is a simple repro: > > ``` > > evantest=# drop table t; > > DROP TABLE > > evantest=# CREATE TABLE t (i int) PARTITION BY RANGE(i); > > CREATE TABLE > > evantest=# CREATE TABLE p0a PARTITION OF t FOR VALUES FROM (0) TO (51); > > CREATE TABLE > > evantest=# CREATE TABLE p0b PARTITION OF t FOR VALUES FROM (51) TO (100); > > CREATE TABLE > > evantest=# \d+ t; > > Partitioned table "public.t" > > Column | Type | Collation | Nullable | Default | Storage | > Compression | Stats target | Description > > > --------+---------+-----------+----------+---------+---------+-------------+--------------+------------- > > i | integer | | | | plain | > | | > > Partition key: RANGE (i) > > Partitions: > > p0a FOR VALUES FROM (0) TO (51) > > p0b FOR VALUES FROM (51) TO (100) > > > > evantest=# ALTER TABLE t SPLIT PARTITION p0a INTO > > evantest-# (PARTITION p0a FOR VALUES FROM (0) TO (53), > > evantest(# PARTITION pdef DEFAULT); > > ALTER TABLE > > evantest=# > > evantest=# > > evantest=# \d+ t; > > Partitioned table "public.t" > > Column | Type | Collation | Nullable | Default | Storage | > Compression | Stats target | Description > > > --------+---------+-----------+----------+---------+---------+-------------+--------------+------------- > > i | integer | | | | plain | > | | > > Partition key: RANGE (i) > > Partitions: > > p0a FOR VALUES FROM (0) TO (53) > > p0b FOR VALUES FROM (51) TO (100) > > pdef DEFAULT > > ``` > > > > As shown above, p0a and p0b now overlap. I think this is a real bug. > > > that's 100% real issue because of planner partition pruning > > ``` > reshke=# CREATE TABLE t (i int) PARTITION BY RANGE(i); > CREATE TABLE > reshke=# CREATE TABLE p0a PARTITION OF t FOR VALUES FROM (0) TO (51); > CREATE TABLE > reshke=# insert into t values (50); > INSERT 0 1 > reshke=# CREATE TABLE p0b PARTITION OF t FOR VALUES FROM (51) TO (100); > CREATE TABLE > reshke=# insert into t values (51); > INSERT 0 1 > reshke=# insert into t values (51); > INSERT 0 1 > reshke=# insert into t values (51); > INSERT 0 1 > reshke=# ALTER TABLE t SPLIT PARTITION p0a INTO(PARTITION p0a FOR > VALUES FROM (0) TO (53),PARTITION pdef DEFAULT); > ALTER TABLE > reshke=# table t; > i > ---- > 50 > 51 > 51 > 51 > (4 rows) > reshke=# select * from t where i = 51; > i > --- > (0 rows) > > reshke=# set enable_partition_pruning to off; > SET > reshke=# select * from t where i = 51; > i > ---- > 51 > 51 > 51 > (3 rows) > > reshke=# > `` > > > > -- > Best regards, > Kirill Reshke > > > I agree this is a bug. I applied the patch locally and confirmed the bug is fixed with the patch. Overall, the patch looks good to me. Regards, Zhenwei Shang
