RE: Disallow UPDATE/DELETE on table with unpublished generated column as REPLICA IDENTITY

On Saturday, November 16, 2024 2:41 AM Shlok Kyal <shlok.kyal.oss@gmail.com> wrote:
> 
> >
> Thanks for providing the comments. I have fixed all the comments and attached
> the updated patch.

Thanks for the patch. I have one comment for the following codes:

+		/*
+		 * Bitmap of published columns when publish_generated_columns is
+		 * 'false' and no column list is specified.
+		 */
+		columns = pub_form_cols_map(relation, false);
+
+		/*
+		 * Attnums in the bitmap returned by RelationGetIndexAttrBitmap are
+		 * offset (to handle system columns the usual way), while column list
+		 * does not use offset, so we can't do bms_is_subset(). Instead, we
+		 * have to loop over the idattrs and check all of them are in the
+		 * list.
+		 */
+		x = -1;
+		while ((x = bms_next_member(idattrs, x)) >= 0)
+		{
...
+		}


It doesn't seem necessary to build a bitmap and then iterator the replica
identity bitmap. Instead, we can efficiently traverse the columns as follows:

for (int i = 0; i < desc->natts; i++)
{
	Form_pg_attribute att = TupleDescAttr(desc, i);

	if (!att->attisdropped && att->attgenerated &&
		bms_is_member(att->attnum - FirstLowInvalidHeapAttributeNumber,
        idattrs))
	{
		result = true;
		break;
	}
}

Best Regards,
Hou zj