Consider the below test:
CREATE TABLE range_tab(a int, b int) PARTITION BY RANGE(a);
CREATE TABLE range_tab_p1 PARTITION OF range_tab FOR VALUES FROM (minvalue) TO (10);
CREATE TABLE range_tab_p2 PARTITION OF range_tab FOR VALUES FROM (10) TO (20);
CREATE TABLE range_tab_p3 PARTITION OF range_tab FOR VALUES FROM (20) TO (maxvalue);
INSERT INTO range_tab VALUES(NULL, 10);
Above insert should fail with an error "no partition of relation found for row".
Looking further I found that, this behaviour is changed after below commit:
commit 4e5fe9ad19e14af360de7970caa8b150436c9dec
Author: Robert Haas <
rhaas@postgresql.org>
Date: Wed Nov 15 10:23:28 2017 -0500
Centralize executor-related partitioning code.
Some code is moved from partition.c, which has grown very quickly lately;
splitting the executor parts out might help to keep it from getting
totally out of control. Other code is moved from execMain.c. All is
moved to a new file execPartition.c. get_partition_for_tuple now has
a new interface that more clearly separates executor concerns from
generic concerns.
Amit Langote. A slight comment tweak by me.
Before above commit insert with NULL partition key in the range partition
was throwing a proper error.
postgres@112171=#INSERT INTO range_tab VALUES(NULL, 10);
ERROR: no partition of relation "range_tab" found for row
DETAIL: Partition key of the failing row contains (a) = (null).
Looking at the code partition_bound_cmp(), before 4e5fe9ad19 commit there
was a condition for the null values:
/*
* No range includes NULL, so this will be accepted by the
* default partition if there is one, and otherwise
* rejected.
*/
for (i = 0; i < key->partnatts; i++)
{
if (isnull[i] &&
partition_bound_has_default(partdesc->boundinfo))
{
range_partkey_has_null = true;
break;
}
Attaching patch to fix as well as regression test.