Currently, check constraints are verified whenever a table row is updated at all. It seems to me that we could possibly make this quite a bit more efficient if we only ran the check constraint expression when the update changes a column that is referenced by the constraint expression. Through dependency tracking, we have that information, and we already have the catalog infrastructure to store this information from primary and foreign keys. We'd just need to do some tweaking in the executor. Any thoughts on that? Possible pitfalls?