Re: disallow alter individual column if partition key contains wholerow reference

On Tue, Oct 28, 2025 at 11:24 PM Kirill Reshke <reshkekirill(at)gmail(dot)com> wrote:
>
> I can see that 0 - FirstLowInvalidHeapAttributeNumber is an existing
> coding practise in sources, but so is
> InvalidAttrNumber - FirstLowInvalidHeapAttributeNumber (sepgsql
> contrib extension). I'm voting for the second one, even though it is
> less used.
>

hi.

now it's:
+ /*
+ * If the partition expression contains a whole-row reference,
+ * then all columns are indirectly associated with that
+ * expression.
+ */
+ if (bms_is_member(InvalidAttrNumber -
FirstLowInvalidHeapAttributeNumber,
+ expr_attrs))
+ {
+ if (used_in_expr)
+ *used_in_expr = true;
+ return true;
+ }

also polished the commit message. below is the commit message:
--------------------------
For partition key expressions containing whole-row reference, we cannot rely on
pg_depend lookups to determine whether an individual column can be altered
(drop, set data type).
As noted in the comments for find_expr_references_walker, no dependency entries
are recorded for whole-row expressions. Therefore whole-row reference check is
needed in has_partition_attrs.

Partition key expressions contain whole-row reference, it is effectively
equivalent to all user columns being indirectly associated with that expression.
Since columns that in a partition key cannot be altered in any way, the same
restriction should be applied to whole-row reference expressions in the
partition key.
--------------------------

--
jian
https://www.enterprisedb.com/