On 31.08.23 12:02, Alvaro Herrera wrote:
In constraint_column_usage, you're adding a relkind to the catalog scan
that goes through pg_depend for CHECK constraints. Here we can rely on
a simple conkey[1] check and a separate UNION ALL arm[q5]; this is also
faster when there are many tables.
The third view definition looks ok. It's certainly very nice to be able
to delete XXX comments there.
The following information schema views are affected by the not-null
constraint catalog entries:
1. CHECK_CONSTRAINTS
2. CONSTRAINT_COLUMN_USAGE
3. DOMAIN_CONSTRAINTS
4. TABLE_CONSTRAINTS
Note that 1 and 3 also contain domain constraints. So as long as the
domain not-null constraints are not similarly catalogued, we can't
delete the separate not-null union branch. (3 never had one, so
arguably a bit buggy.)
I think we can fix up 4 by just deleting the not-null union branch.
For 2, the simple fix is also easy, but there are some other options, as
you discuss above.
How do you want to proceed?
