public inbox for [email protected]
help / color / mirror / Atom feedFrom: Chao Li <[email protected]>
To: Alexander Korotkov <[email protected]>
Cc: Dmitry Koval <[email protected]>
Cc: PostgreSQL-development <[email protected]>
Subject: Re: Fix SPLIT PARTITION bound-overlap bug and other improvements
Date: Tue, 19 May 2026 10:50:03 +0800
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAPpHfduMLJkOSguaKhm4PEWRYHqqvFDX6bu5+E_LSxuy5YjPEw@mail.gmail.com>
References: <[email protected]>
<[email protected]>
<[email protected]>
<CAPpHfdvdevTMpjQe09aWdK_nbrE4+M1z09H2SUe3bgxY3_QUdA@mail.gmail.com>
<[email protected]>
<CAPpHfdsLnD3NGnPC32oeg4ZWWX441M=SfH0-7bG652G40TpEEQ@mail.gmail.com>
<[email protected]>
<CAPpHfduMLJkOSguaKhm4PEWRYHqqvFDX6bu5+E_LSxuy5YjPEw@mail.gmail.com>
> On May 18, 2026, at 20:04, Alexander Korotkov <[email protected]> wrote:
>
> On Mon, May 18, 2026 at 2:57 PM Chao Li <[email protected]> wrote:
>>> <v3-0003-Clarify-SPLIT-PARTITION-bound-requirements-in-doc.patch><v3-0001-Fix-SPLIT-PARTITION-range-bound-validation-with-D.patch><v3-0002-Fix-SPLIT-PARTITION-hint-for-DEFAULT-partition-bo.patch><v3-0004-Reject-degenerate-SPLIT-PARTITION-with-DEFAULT-pa.patch>
>>
>> v3-0001 through v3-0003 look good to me.
>>
>> For v3-0004, I have a suspicion, but it's late here and my brain is getting slow, so I would like to study it more tomorrow.
>
> Sure, take your time.
>
> ------
> Regards,
> Alexander Korotkov
> Supabase
My suspicion was that check_split_partition_not_same_bound() now has two paths. The RANGE path honors collation, while the LIST path does not. So I spent some time creating a test that uses a case-insensitive collation:
```
evantest=# create collation case_insensitive (provider=icu, locale='und-u-ks-level2', deterministic = false);
CREATE COLLATION
evantest=# create table t (b text collate case_insensitive) partition by list (b);
CREATE TABLE
evantest=# create table tp_ab partition of t for values in ('a', 'b');
CREATE TABLE
evantest=# alter table t split partition tp_ab into
evantest-# (partition tp_a for values in ('a', 'A'),
evantest(# partition tp_default default);
ERROR: cannot split partition "tp_ab" only to add a DEFAULT partition
LINE 2: (partition tp_a for values in ('a', 'A'),
^
DETAIL: The non-DEFAULT partition would keep the same partition bound.
HINT: Use CREATE TABLE ... PARTITION OF ... DEFAULT to add a DEFAULT partition.
```
In this test, the split partition’s bound is ('a', 'b'), and the new partition’s bound is ('a', 'A'). Their list lengths are both 2, but the two bounds are actually different, because 'a' and 'A' are considered equal by the collation.
So, in the LIST path, since check_partition_bounds_for_split_list() has already ensured that the new partition’s bound is contained within the split partition’s bound, we need to check the reverse direction as well. Whether the split partition’s bound is also contained in the new partition’s bound. If yes, the two bounds are identical.
See the attached v4 for my changes for 0004. 0001-0003 are unchanged. Since 0001 and 0003 are independent of 0004, maybe they can be pushed first.
Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/
Attachments:
[application/octet-stream] v4-0001-Fix-SPLIT-PARTITION-range-bound-validation-with-D.patch (4.1K, 2-v4-0001-Fix-SPLIT-PARTITION-range-bound-validation-with-D.patch)
download | inline diff:
From cc401a3a77bc84e6e890ce4cef3e28ece8f284e0 Mon Sep 17 00:00:00 2001
From: Alexander Korotkov <[email protected]>
Date: Mon, 18 May 2026 00:36:23 +0300
Subject: [PATCH v4 1/4] Fix SPLIT PARTITION range bound validation with
DEFAULT
When splitting a range partition and defining a new DEFAULT partition, the
validation checked the lower bound of the first explicit partition and the
upper bound of explicit partitions only when they were not first. If there
was exactly one explicit non-DEFAULT partition, its upper bound was therefore
not checked.
This could allow the replacement partition to extend beyond the upper bound
of the partition being split, potentially overlapping another existing
partition.
Fix this by checking the upper bound whenever the explicit partition is the
last one. Add a regression test covering the single explicit partition plus
DEFAULT case.
Author: Chao Li <[email protected]>
Reviewed-by: Kirill Reshke <[email protected]>
Reviewed-by: Zhenwei Shang <[email protected]>
Reviewed-by: Dmitry Koval <[email protected]>
Reviewed-by: Alexander Korotkov <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
src/backend/partitioning/partbounds.c | 3 ++-
src/test/regress/expected/partition_split.out | 16 ++++++++++++++++
src/test/regress/sql/partition_split.sql | 15 +++++++++++++++
3 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/src/backend/partitioning/partbounds.c b/src/backend/partitioning/partbounds.c
index a09beec34d8..73dea0375be 100644
--- a/src/backend/partitioning/partbounds.c
+++ b/src/backend/partitioning/partbounds.c
@@ -5419,7 +5419,8 @@ check_partition_bounds_for_split_range(Relation parent,
"ALTER TABLE ... SPLIT PARTITION"),
parser_errposition(pstate, exprLocation((Node *) datum)));
}
- else
+
+ if (last)
{
PartitionRangeBound *split_upper;
diff --git a/src/test/regress/expected/partition_split.out b/src/test/regress/expected/partition_split.out
index 961b37953c8..a2ccbe5138b 100644
--- a/src/test/regress/expected/partition_split.out
+++ b/src/test/regress/expected/partition_split.out
@@ -1188,6 +1188,22 @@ SELECT tableoid::regclass, * FROM sales_range ORDER BY tableoid::regclass::text
DROP TABLE sales_range;
--
+-- Test that the explicit partition bound cannot extend outside the split
+-- partition's bound when a DEFAULT partition is specified.
+--
+CREATE TABLE t (i int) PARTITION BY RANGE (i);
+CREATE TABLE tp_0_51 PARTITION OF t FOR VALUES FROM (0) TO (51);
+CREATE TABLE tp_51_100 PARTITION OF t FOR VALUES FROM (51) TO (100);
+-- ERROR
+ALTER TABLE t SPLIT PARTITION tp_0_51 INTO
+ (PARTITION tp_0_51 FOR VALUES FROM (0) TO (53),
+ PARTITION tp_default DEFAULT);
+ERROR: upper bound of partition "tp_0_51" is greater than upper bound of split partition "tp_0_51"
+LINE 2: (PARTITION tp_0_51 FOR VALUES FROM (0) TO (53),
+ ^
+HINT: ALTER TABLE ... SPLIT PARTITION require combined bounds of new partitions must exactly match the bound of the split partition.
+DROP TABLE t;
+--
-- Try to SPLIT partition of another table.
--
CREATE TABLE t1(i int, t text) PARTITION BY LIST (t);
diff --git a/src/test/regress/sql/partition_split.sql b/src/test/regress/sql/partition_split.sql
index a110fc87867..d9821c5e2a3 100644
--- a/src/test/regress/sql/partition_split.sql
+++ b/src/test/regress/sql/partition_split.sql
@@ -834,6 +834,21 @@ SELECT tableoid::regclass, * FROM sales_range ORDER BY tableoid::regclass::text
DROP TABLE sales_range;
+--
+-- Test that the explicit partition bound cannot extend outside the split
+-- partition's bound when a DEFAULT partition is specified.
+--
+CREATE TABLE t (i int) PARTITION BY RANGE (i);
+CREATE TABLE tp_0_51 PARTITION OF t FOR VALUES FROM (0) TO (51);
+CREATE TABLE tp_51_100 PARTITION OF t FOR VALUES FROM (51) TO (100);
+
+-- ERROR
+ALTER TABLE t SPLIT PARTITION tp_0_51 INTO
+ (PARTITION tp_0_51 FOR VALUES FROM (0) TO (53),
+ PARTITION tp_default DEFAULT);
+
+DROP TABLE t;
+
--
-- Try to SPLIT partition of another table.
--
--
2.50.1 (Apple Git-155)
[application/octet-stream] v4-0002-Fix-SPLIT-PARTITION-hint-for-DEFAULT-partition-bo.patch (10.1K, 3-v4-0002-Fix-SPLIT-PARTITION-hint-for-DEFAULT-partition-bo.patch)
download | inline diff:
From 57dea552776e487dc3a10858238e33ed2aa94700 Mon Sep 17 00:00:00 2001
From: Alexander Korotkov <[email protected]>
Date: Mon, 18 May 2026 00:36:44 +0300
Subject: [PATCH v4 2/4] Fix SPLIT PARTITION hint for DEFAULT partition bounds
When ALTER TABLE ... SPLIT PARTITION specifies a DEFAULT partition, the
explicit partitions do not need to cover the split partition's bound
exactly. They may cover only part of it, with the DEFAULT partition
covering the remaining range.
However, the existing hint said that the combined bounds of the new
partitions must exactly match the bound of the split partition, which is
misleading for this case and inconsistent with the code comment.
Fix the hint to state the actual requirement: explicit partition bounds
must stay within the bounds of the split partition when a DEFAULT
partition is specified.
Author: Chao Li <[email protected]>
Reviewed-by: Alexander Korotkov <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
src/backend/partitioning/partbounds.c | 14 ++++++--------
src/test/regress/expected/partition_split.out | 14 +++++++-------
2 files changed, 13 insertions(+), 15 deletions(-)
diff --git a/src/backend/partitioning/partbounds.c b/src/backend/partitioning/partbounds.c
index 73dea0375be..7d3580cbc10 100644
--- a/src/backend/partitioning/partbounds.c
+++ b/src/backend/partitioning/partbounds.c
@@ -5405,7 +5405,7 @@ check_partition_bounds_for_split_range(Relation parent,
errmsg("lower bound of partition \"%s\" is not equal to lower bound of split partition \"%s\"",
relname,
get_rel_name(splitPartOid)),
- errhint("%s require combined bounds of new partitions must exactly match the bound of the split partition.",
+ errhint("%s requires the combined bounds of the new partitions to exactly match the bound of the split partition.",
"ALTER TABLE ... SPLIT PARTITION"),
parser_errposition(pstate, exprLocation((Node *) datum)));
}
@@ -5415,8 +5415,7 @@ check_partition_bounds_for_split_range(Relation parent,
errmsg("lower bound of partition \"%s\" is less than lower bound of split partition \"%s\"",
relname,
get_rel_name(splitPartOid)),
- errhint("%s require combined bounds of new partitions must exactly match the bound of the split partition.",
- "ALTER TABLE ... SPLIT PARTITION"),
+ errhint("Explicit partition bounds must be contained within the bounds of the split partition when a DEFAULT partition is specified."),
parser_errposition(pstate, exprLocation((Node *) datum)));
}
@@ -5448,7 +5447,7 @@ check_partition_bounds_for_split_range(Relation parent,
errmsg("upper bound of partition \"%s\" is not equal to upper bound of split partition \"%s\"",
relname,
get_rel_name(splitPartOid)),
- errhint("%s require combined bounds of new partitions must exactly match the bound of the split partition.",
+ errhint("%s requires the combined bounds of the new partitions to exactly match the bound of the split partition.",
"ALTER TABLE ... SPLIT PARTITION"),
parser_errposition(pstate, exprLocation((Node *) datum)));
}
@@ -5458,8 +5457,7 @@ check_partition_bounds_for_split_range(Relation parent,
errmsg("upper bound of partition \"%s\" is greater than upper bound of split partition \"%s\"",
relname,
get_rel_name(splitPartOid)),
- errhint("%s require combined bounds of new partitions must exactly match the bound of the split partition.",
- "ALTER TABLE ... SPLIT PARTITION"),
+ errhint("Explicit partition bounds must be contained within the bounds of the split partition when a DEFAULT partition is specified."),
parser_errposition(pstate, exprLocation((Node *) datum)));
}
}
@@ -5654,7 +5652,7 @@ check_parent_values_in_new_partitions(Relation parent,
errmsg("new partitions' combined partition bounds do not contain value (%s) but split partition \"%s\" does",
"NULL",
get_rel_name(partOid)),
- errhint("%s require combined bounds of new partitions must exactly match the bound of the split partition.",
+ errhint("%s requires the combined bounds of the new partitions to exactly match the bound of the split partition.",
"ALTER TABLE ... SPLIT PARTITION"));
/*
@@ -5697,7 +5695,7 @@ check_parent_values_in_new_partitions(Relation parent,
errmsg("new partitions' combined partition bounds do not contain value (%s) but split partition \"%s\" does",
deparse_expression((Node *) notFoundVal, NIL, false, false),
get_rel_name(partOid)),
- errhint("%s require combined bounds of new partitions must exactly match the bound of the split partition.",
+ errhint("%s requires the combined bounds of the new partitions to exactly match the bound of the split partition.",
"ALTER TABLE ... SPLIT PARTITION"));
}
}
diff --git a/src/test/regress/expected/partition_split.out b/src/test/regress/expected/partition_split.out
index a2ccbe5138b..2b9a6aa50ed 100644
--- a/src/test/regress/expected/partition_split.out
+++ b/src/test/regress/expected/partition_split.out
@@ -56,7 +56,7 @@ ALTER TABLE sales_range SPLIT PARTITION sales_feb_mar_apr2022 INTO
ERROR: lower bound of partition "sales_feb2022" is not equal to lower bound of split partition "sales_feb_mar_apr2022"
LINE 2: (PARTITION sales_feb2022 FOR VALUES FROM ('2022-01-01') TO...
^
-HINT: ALTER TABLE ... SPLIT PARTITION require combined bounds of new partitions must exactly match the bound of the split partition.
+HINT: ALTER TABLE ... SPLIT PARTITION requires the combined bounds of the new partitions to exactly match the bound of the split partition.
-- ERROR
-- (We can create partition with the same name as split partition, but can't create two partitions with the same name)
ALTER TABLE sales_range SPLIT PARTITION sales_feb_mar_apr2022 INTO
@@ -97,7 +97,7 @@ ALTER TABLE sales_range SPLIT PARTITION sales_feb_mar_apr2022 INTO
ERROR: upper bound of partition "sales_apr2022" is not equal to upper bound of split partition "sales_feb_mar_apr2022"
LINE 4: ... sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-06-0...
^
-HINT: ALTER TABLE ... SPLIT PARTITION require combined bounds of new partitions must exactly match the bound of the split partition.
+HINT: ALTER TABLE ... SPLIT PARTITION requires the combined bounds of the new partitions to exactly match the bound of the split partition.
-- ERROR
ALTER TABLE sales_range SPLIT PARTITION sales_feb_mar_apr2022 INTO
(PARTITION sales_feb2022 FOR VALUES FROM ('2022-02-01') TO ('2022-03-01'),
@@ -118,7 +118,7 @@ ALTER TABLE sales_range SPLIT PARTITION sales_feb_mar_apr2022 INTO
ERROR: lower bound of partition "sales_feb2022" is not equal to lower bound of split partition "sales_feb_mar_apr2022"
LINE 2: (PARTITION sales_feb2022 FOR VALUES FROM ('2022-02-02') TO...
^
-HINT: ALTER TABLE ... SPLIT PARTITION require combined bounds of new partitions must exactly match the bound of the split partition.
+HINT: ALTER TABLE ... SPLIT PARTITION requires the combined bounds of the new partitions to exactly match the bound of the split partition.
-- Check the source partition not in the search path
SET search_path = partition_split_schema2, public;
ALTER TABLE partition_split_schema.sales_range
@@ -154,7 +154,7 @@ ALTER TABLE sales_range SPLIT PARTITION sales_feb_mar_apr2022 INTO
ERROR: upper bound of partition "sales_apr2022" is not equal to upper bound of split partition "sales_feb_mar_apr2022"
LINE 4: ... sales_apr2022 FOR VALUES FROM ('2022-04-01') TO ('2022-06-0...
^
-HINT: ALTER TABLE ... SPLIT PARTITION require combined bounds of new partitions must exactly match the bound of the split partition.
+HINT: ALTER TABLE ... SPLIT PARTITION requires the combined bounds of the new partitions to exactly match the bound of the split partition.
DROP TABLE sales_range;
--
-- Add rows into partitioned table then split partition
@@ -917,14 +917,14 @@ ALTER TABLE sales_list SPLIT PARTITION sales_all INTO
PARTITION sales_east FOR VALUES IN ('Beijing', 'Delhi', 'Vladivostok'),
PARTITION sales_central FOR VALUES IN ('Warsaw', 'Berlin', 'Kyiv'));
ERROR: new partitions' combined partition bounds do not contain value (NULL) but split partition "sales_all" does
-HINT: ALTER TABLE ... SPLIT PARTITION require combined bounds of new partitions must exactly match the bound of the split partition.
+HINT: ALTER TABLE ... SPLIT PARTITION requires the combined bounds of the new partitions to exactly match the bound of the split partition.
-- ERROR
ALTER TABLE sales_list SPLIT PARTITION sales_all INTO
(PARTITION sales_west FOR VALUES IN ('Lisbon', 'New York', 'Madrid'),
PARTITION sales_east FOR VALUES IN ('Beijing', 'Delhi', 'Vladivostok'),
PARTITION sales_central FOR VALUES IN ('Warsaw', 'Berlin', NULL));
ERROR: new partitions' combined partition bounds do not contain value ('Kyiv'::character varying(20)) but split partition "sales_all" does
-HINT: ALTER TABLE ... SPLIT PARTITION require combined bounds of new partitions must exactly match the bound of the split partition.
+HINT: ALTER TABLE ... SPLIT PARTITION requires the combined bounds of the new partitions to exactly match the bound of the split partition.
-- ERROR
ALTER TABLE sales_list SPLIT PARTITION sales_all INTO
(PARTITION sales_west FOR VALUES IN ('Lisbon', 'New York', 'Madrid'),
@@ -1201,7 +1201,7 @@ ALTER TABLE t SPLIT PARTITION tp_0_51 INTO
ERROR: upper bound of partition "tp_0_51" is greater than upper bound of split partition "tp_0_51"
LINE 2: (PARTITION tp_0_51 FOR VALUES FROM (0) TO (53),
^
-HINT: ALTER TABLE ... SPLIT PARTITION require combined bounds of new partitions must exactly match the bound of the split partition.
+HINT: Explicit partition bounds must be contained within the bounds of the split partition when a DEFAULT partition is specified.
DROP TABLE t;
--
-- Try to SPLIT partition of another table.
--
2.50.1 (Apple Git-155)
[application/octet-stream] v4-0003-Clarify-SPLIT-PARTITION-bound-requirements-in-doc.patch (3.8K, 4-v4-0003-Clarify-SPLIT-PARTITION-bound-requirements-in-doc.patch)
download | inline diff:
From 4c1be7b104c4dc507384e7e63de8b491d6ae3f37 Mon Sep 17 00:00:00 2001
From: Alexander Korotkov <[email protected]>
Date: Mon, 18 May 2026 00:37:06 +0300
Subject: [PATCH v4 3/4] Clarify SPLIT PARTITION bound requirements in docs
The documentation said that the bounds of new partitions should not
overlap and that their combined bounds should equal the bounds of the
split partition. That is misleading when a new DEFAULT partition is
specified, because the explicit partitions may cover only part of the
split partition while the DEFAULT partition covers the rest.
Clarify that new non-DEFAULT partition bounds must not overlap with
other new or existing partitions and must be contained within the bounds
of the split partition. Also state that the combined bounds must exactly
match the split partition only when no new DEFAULT partition is specified.
While here, improve nearby wording about hash-partitioned target tables
and splitting a DEFAULT partition with the same partition name.
Author: Chao Li <[email protected]>
Reviewed-by: Alexander Korotkov <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
doc/src/sgml/ref/alter_table.sgml | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index 1f9a456fd33..dec34337d1a 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -1293,7 +1293,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<listitem>
<para>
This form splits a single partition of the target table into new
- partitions. Hash-partitioned target table is not supported.
+ partitions. Hash-partitioned target tables are not supported.
Only a simple, non-partitioned partition can be split.
If the split partition is the <literal>DEFAULT</literal> partition,
one of the new partitions must be <literal>DEFAULT</literal>.
@@ -1303,18 +1303,23 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
</para>
<para>
- The bounds of new partitions should not overlap with those of new or
- existing partitions (except <replaceable class="parameter">partition_name</replaceable>).
- The combined bounds of new partitions <literal>
+ The bounds of new non-<literal>DEFAULT</literal> partitions must not
+ overlap with those of new or existing partitions, except
+ <replaceable class="parameter">partition_name</replaceable>, and must be
+ contained within the bounds of the split partition
+ <replaceable class="parameter">partition_name</replaceable>.
+ If no new <literal>DEFAULT</literal> partition is specified, the
+ combined bounds of the new partitions
+ <literal>
<replaceable class="parameter">partition_name1</replaceable>,
<replaceable class="parameter">partition_name2</replaceable>[, ...]
- </literal> should be equal to the bounds of the split partition
+ </literal> must exactly match the bounds of the split partition
<replaceable class="parameter">partition_name</replaceable>.
One of the new partitions can have the same name as the split partition
- <replaceable class="parameter">partition_name</replaceable>
- (this is suitable in case of splitting the <literal>DEFAULT</literal>
- partition: after the split, the <literal>DEFAULT</literal> partition
- remains with the same name, but its partition bound changes).
+ <replaceable class="parameter">partition_name</replaceable>.
+ This is useful when splitting the <literal>DEFAULT</literal> partition,
+ so that after the split, the <literal>DEFAULT</literal> partition
+ keeps the same name but its partition bound changes.
</para>
<para>
--
2.50.1 (Apple Git-155)
[application/octet-stream] v4-0004-Reject-degenerate-SPLIT-PARTITION-with-DEFAULT-pa.patch (11.9K, 5-v4-0004-Reject-degenerate-SPLIT-PARTITION-with-DEFAULT-pa.patch)
download | inline diff:
From 3c033ade957420ffcc5fcac8f925a6c9a7a9f009 Mon Sep 17 00:00:00 2001
From: Alexander Korotkov <[email protected]>
Date: Mon, 18 May 2026 00:37:52 +0300
Subject: [PATCH v4 4/4] Reject degenerate SPLIT PARTITION with DEFAULT
partition
ALTER TABLE ... SPLIT PARTITION allows a DEFAULT partition to be created
as one of the replacement partitions when the parent table does not
already have one. However, it should not allow the degenerate case where
a non-DEFAULT partition keeps exactly the same bound as the split
partition and the command merely adds a DEFAULT partition through the
SPLIT PARTITION path.
Detect that case by comparing the bound of the split partition with the
bound of the only non-DEFAULT replacement partition, and raise an error
when they are the same. Users should add a DEFAULT partition directly
with CREATE TABLE ... PARTITION OF ... DEFAULT or ALTER TABLE ... ATTACH
PARTITION ... DEFAULT instead.
Author: Chao Li <[email protected]>
Reviewed-by: Alexander Korotkov <[email protected]>
Discussion: https://postgr.es/m/[email protected]
---
src/backend/partitioning/partbounds.c | 145 ++++++++++++++++++
src/test/regress/expected/partition_split.out | 59 +++++++
src/test/regress/sql/partition_split.sql | 52 +++++++
3 files changed, 256 insertions(+)
diff --git a/src/backend/partitioning/partbounds.c b/src/backend/partitioning/partbounds.c
index 7d3580cbc10..126a9be15ba 100644
--- a/src/backend/partitioning/partbounds.c
+++ b/src/backend/partitioning/partbounds.c
@@ -5700,6 +5700,141 @@ check_parent_values_in_new_partitions(Relation parent,
}
}
+/*
+ * split_partition_values_contained_in_new_part
+ *
+ * (function for BY LIST partitioning)
+ *
+ * Returns true if all values in the LIST bound of the partition being split
+ * are contained in the specified non-DEFAULT replacement partition's bound.
+ *
+ * The caller must already have verified containment in the other direction,
+ * so this check is sufficient to prove that the two LIST bounds are equal.
+ */
+static bool
+split_partition_values_contained_in_new_part(Relation parent,
+ Oid splitPartOid,
+ SinglePartitionSpec *part)
+{
+ PartitionKey key = RelationGetPartitionKey(parent);
+ PartitionDesc partdesc = RelationGetPartitionDesc(parent, false);
+ PartitionBoundInfo boundinfo = partdesc->boundinfo;
+ SinglePartitionSpec *parts[1];
+ Datum datum = PointerGetDatum(NULL);
+
+ Assert(key->strategy == PARTITION_STRATEGY_LIST);
+
+ parts[0] = part;
+
+ /*
+ * Special processing for NULL value. Search for a NULL value if the
+ * split partition contains it.
+ */
+ if (partition_bound_accepts_nulls(boundinfo) &&
+ partdesc->oids[boundinfo->null_index] == splitPartOid)
+ {
+ if (!find_value_in_new_partitions_list(&key->partsupfunc[0],
+ key->partcollation, parts, 1,
+ datum, true))
+ return false;
+ }
+
+ /*
+ * Search all values of the split partition in the single non-DEFAULT
+ * replacement partition.
+ */
+ for (int i = 0; i < boundinfo->ndatums; i++)
+ {
+ if (partdesc->oids[boundinfo->indexes[i]] == splitPartOid)
+ {
+ datum = boundinfo->datums[i][0];
+
+ if (!find_value_in_new_partitions_list(&key->partsupfunc[0],
+ key->partcollation, parts, 1,
+ datum, false))
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/*
+ * check_split_partition_not_same_bound
+ *
+ * Reject splitting a non-DEFAULT partition into one non-DEFAULT partition
+ * with the original bound plus a DEFAULT partition. That form does not
+ * perform a real split; it merely adds a DEFAULT partition to the parent
+ * table through the split-partition path. Users should use
+ * CREATE TABLE ... PARTITION OF ... DEFAULT or ALTER TABLE ... ATTACH
+ * PARTITION ... DEFAULT for that.
+ *
+ * Must be called after the per-partition bound validation in
+ * check_partitions_for_split() so that containment of new bounds within the
+ * split partition is already established. Given containment, RANGE bounds
+ * are equal iff their lower and upper rbounds match; LIST bound sets are
+ * equal iff the split partition's values are also contained in the new
+ * partition.
+ */
+static void
+check_split_partition_not_same_bound(Relation parent,
+ Oid splitPartOid,
+ SinglePartitionSpec **parts,
+ int nparts,
+ ParseState *pstate)
+{
+ PartitionKey key = RelationGetPartitionKey(parent);
+ PartitionBoundSpec *new_spec;
+ PartitionBoundSpec *split_spec;
+
+ if (nparts != 1)
+ return;
+
+ new_spec = parts[0]->bound;
+ split_spec = get_partition_bound_spec(splitPartOid);
+
+ Assert(new_spec->strategy == split_spec->strategy);
+
+ if (key->strategy == PARTITION_STRATEGY_RANGE)
+ {
+ PartitionRangeBound *new_lower;
+ PartitionRangeBound *new_upper;
+ PartitionRangeBound *split_lower;
+ PartitionRangeBound *split_upper;
+
+ new_lower = make_one_partition_rbound(key, -1, new_spec->lowerdatums, true);
+ new_upper = make_one_partition_rbound(key, -1, new_spec->upperdatums, false);
+ split_lower = make_one_partition_rbound(key, -1, split_spec->lowerdatums, true);
+ split_upper = make_one_partition_rbound(key, -1, split_spec->upperdatums, false);
+
+ if (partition_rbound_cmp(key->partnatts, key->partsupfunc,
+ key->partcollation,
+ new_lower->datums, new_lower->kind, true,
+ split_lower) != 0)
+ return;
+ if (partition_rbound_cmp(key->partnatts, key->partsupfunc,
+ key->partcollation,
+ new_upper->datums, new_upper->kind, false,
+ split_upper) != 0)
+ return;
+ }
+ else
+ {
+ Assert(key->strategy == PARTITION_STRATEGY_LIST);
+
+ if (!split_partition_values_contained_in_new_part(parent, splitPartOid, parts[0]))
+ return;
+ }
+
+ ereport(ERROR,
+ errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+ errmsg("cannot split partition \"%s\" only to add a DEFAULT partition",
+ get_rel_name(splitPartOid)),
+ errdetail("The non-DEFAULT partition would keep the same partition bound."),
+ errhint("Use CREATE TABLE ... PARTITION OF ... DEFAULT to add a DEFAULT partition."),
+ parser_errposition(pstate, parts[0]->name->location));
+}
+
/*
* check_partitions_for_split
*
@@ -5871,5 +6006,15 @@ check_partitions_for_split(Relation parent,
new_parts, nparts, pstate);
}
+ /*
+ * Reject the degenerate form where the single non-DEFAULT replacement
+ * partition keeps the bound of the split partition; the command then does
+ * nothing beyond adding a DEFAULT partition. Containment was established
+ * by the per-partition validation above, so an equality check is enough.
+ */
+ if (!isSplitPartDefault && createDefaultPart)
+ check_split_partition_not_same_bound(parent, splitPartOid, new_parts,
+ nparts, pstate);
+
pfree(new_parts);
}
diff --git a/src/test/regress/expected/partition_split.out b/src/test/regress/expected/partition_split.out
index 2b9a6aa50ed..2fd9aee1dcc 100644
--- a/src/test/regress/expected/partition_split.out
+++ b/src/test/regress/expected/partition_split.out
@@ -1188,6 +1188,65 @@ SELECT tableoid::regclass, * FROM sales_range ORDER BY tableoid::regclass::text
DROP TABLE sales_range;
--
+-- Test that SPLIT PARTITION rejects the degenerate case where the only
+-- non-DEFAULT replacement partition keeps the original bound and the command
+-- merely adds a DEFAULT partition.
+--
+CREATE TABLE t (i int) PARTITION BY RANGE (i);
+CREATE TABLE tp_0_50 PARTITION OF t FOR VALUES FROM (0) TO (50);
+INSERT INTO t VALUES (1);
+-- ERROR
+ALTER TABLE t SPLIT PARTITION tp_0_50 INTO
+ (PARTITION tp_0_50 FOR VALUES FROM (0) TO (50),
+ PARTITION tp_default DEFAULT);
+ERROR: cannot split partition "tp_0_50" only to add a DEFAULT partition
+LINE 2: (PARTITION tp_0_50 FOR VALUES FROM (0) TO (50),
+ ^
+DETAIL: The non-DEFAULT partition would keep the same partition bound.
+HINT: Use CREATE TABLE ... PARTITION OF ... DEFAULT to add a DEFAULT partition.
+DROP TABLE t;
+--
+-- Test that a LIST split with DEFAULT is not considered degenerate when
+-- only NULL is removed from the explicit replacement partition.
+--
+CREATE TABLE t (i int) PARTITION BY LIST (i);
+CREATE TABLE tp_null_1 PARTITION OF t FOR VALUES IN (NULL, 1);
+ALTER TABLE t SPLIT PARTITION tp_null_1 INTO
+ (PARTITION tp_1 FOR VALUES IN (1),
+ PARTITION tp_default DEFAULT);
+INSERT INTO t VALUES (NULL), (1), (2);
+SELECT tableoid::regclass, i FROM t ORDER BY tableoid::regclass::text COLLATE "C", i NULLS FIRST;
+ tableoid | i
+------------+---
+ tp_1 | 1
+ tp_default |
+ tp_default | 2
+(3 rows)
+
+DROP TABLE t;
+--
+-- Test that the same-bound check for LIST partitioning uses partition
+-- comparison semantics, not raw list length. The case-insensitive collation
+-- treats 'a' and 'A' as equal, so the non-DEFAULT replacement partition
+-- covers only the 'a' group and the DEFAULT partition covers the rest.
+--
+CREATE COLLATION case_insensitive (provider = icu, locale = 'und-u-ks-level2', deterministic = false);
+CREATE TABLE t (b text COLLATE case_insensitive) PARTITION BY LIST (b);
+CREATE TABLE tp_ab PARTITION OF t FOR VALUES IN ('a', 'b');
+ALTER TABLE t SPLIT PARTITION tp_ab INTO
+ (PARTITION tp_a FOR VALUES IN ('a', 'A'),
+ PARTITION tp_default DEFAULT);
+INSERT INTO t VALUES ('a'), ('A'), ('b'), ('c');
+SELECT tableoid::regclass, count(*) FROM t GROUP BY 1 ORDER BY 1;
+ tableoid | count
+------------+-------
+ tp_a | 2
+ tp_default | 2
+(2 rows)
+
+DROP TABLE t;
+DROP COLLATION case_insensitive;
+--
-- Test that the explicit partition bound cannot extend outside the split
-- partition's bound when a DEFAULT partition is specified.
--
diff --git a/src/test/regress/sql/partition_split.sql b/src/test/regress/sql/partition_split.sql
index d9821c5e2a3..ede89ad0228 100644
--- a/src/test/regress/sql/partition_split.sql
+++ b/src/test/regress/sql/partition_split.sql
@@ -834,6 +834,58 @@ SELECT tableoid::regclass, * FROM sales_range ORDER BY tableoid::regclass::text
DROP TABLE sales_range;
+--
+-- Test that SPLIT PARTITION rejects the degenerate case where the only
+-- non-DEFAULT replacement partition keeps the original bound and the command
+-- merely adds a DEFAULT partition.
+--
+CREATE TABLE t (i int) PARTITION BY RANGE (i);
+CREATE TABLE tp_0_50 PARTITION OF t FOR VALUES FROM (0) TO (50);
+INSERT INTO t VALUES (1);
+
+-- ERROR
+ALTER TABLE t SPLIT PARTITION tp_0_50 INTO
+ (PARTITION tp_0_50 FOR VALUES FROM (0) TO (50),
+ PARTITION tp_default DEFAULT);
+
+DROP TABLE t;
+
+--
+-- Test that a LIST split with DEFAULT is not considered degenerate when
+-- only NULL is removed from the explicit replacement partition.
+--
+CREATE TABLE t (i int) PARTITION BY LIST (i);
+CREATE TABLE tp_null_1 PARTITION OF t FOR VALUES IN (NULL, 1);
+
+ALTER TABLE t SPLIT PARTITION tp_null_1 INTO
+ (PARTITION tp_1 FOR VALUES IN (1),
+ PARTITION tp_default DEFAULT);
+
+INSERT INTO t VALUES (NULL), (1), (2);
+SELECT tableoid::regclass, i FROM t ORDER BY tableoid::regclass::text COLLATE "C", i NULLS FIRST;
+
+DROP TABLE t;
+
+--
+-- Test that the same-bound check for LIST partitioning uses partition
+-- comparison semantics, not raw list length. The case-insensitive collation
+-- treats 'a' and 'A' as equal, so the non-DEFAULT replacement partition
+-- covers only the 'a' group and the DEFAULT partition covers the rest.
+--
+CREATE COLLATION case_insensitive (provider = icu, locale = 'und-u-ks-level2', deterministic = false);
+CREATE TABLE t (b text COLLATE case_insensitive) PARTITION BY LIST (b);
+CREATE TABLE tp_ab PARTITION OF t FOR VALUES IN ('a', 'b');
+
+ALTER TABLE t SPLIT PARTITION tp_ab INTO
+ (PARTITION tp_a FOR VALUES IN ('a', 'A'),
+ PARTITION tp_default DEFAULT);
+
+INSERT INTO t VALUES ('a'), ('A'), ('b'), ('c');
+SELECT tableoid::regclass, count(*) FROM t GROUP BY 1 ORDER BY 1;
+
+DROP TABLE t;
+DROP COLLATION case_insensitive;
+
--
-- Test that the explicit partition bound cannot extend outside the split
-- partition's bound when a DEFAULT partition is specified.
--
2.50.1 (Apple Git-155)
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected], [email protected]
Subject: Re: Fix SPLIT PARTITION bound-overlap bug and other improvements
In-Reply-To: <[email protected]>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox