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 numeric_literal, REM
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 DEFAULT partition,
one of the new partitions must be DEFAULT.
@@ -1303,18 +1303,23 @@ WITH ( MODULUS numeric_literal, REM
- The bounds of new partitions should not overlap with those of new or
- existing partitions (except partition_name).
- The combined bounds of new partitions
+ The bounds of new non-DEFAULT partitions must not
+ overlap with those of new or existing partitions, except
+ partition_name, and must be
+ contained within the bounds of the split partition
+ partition_name.
+ If no new DEFAULT partition is specified, the
+ combined bounds of the new partitions
+
partition_name1,
partition_name2[, ...]
- should be equal to the bounds of the split partition
+ must exactly match the bounds of the split partition
partition_name.
One of the new partitions can have the same name as the split partition
- partition_name
- (this is suitable in case of splitting the DEFAULT
- partition: after the split, the DEFAULT partition
- remains with the same name, but its partition bound changes).
+ partition_name.
+ This is useful when splitting the DEFAULT partition,
+ so that after the split, the DEFAULT partition
+ keeps the same name but its partition bound changes.