Re: Two questions about "pg_constraint"

[Bryn Llewellyn <bryn@xxxxxxxxxxxx>]

That's the answer I was seeking. So it's case closed for both of my « Two questions about "pg_constraint" ». Thanks, Tom. And thanks to the others who've contributed to this thread.

tgl@xxxxxxxxxxxxx wrote:

bryn@xxxxxxxxxxxx writes:

My other question was about the "connamespace" column. It seemed to me, both at first and still now, that this is a clear instance of a transitive dependency.

I think a more productive way to think about it is that it's denormalization for efficiency; specifically to let constraints be looked up by name+namespace without having to get other catalogs involved.  (SET CONSTRAINTS is one thing that requires that, and I think there are others.)