Re: cataloguing NOT NULL constraints

Hello,

While discussing the matter of multiple constraints with Vik Fearing, I
noticed that we were throwing an unnecessary error if you used

CREATE TABLE foo (a int NOT NULL NOT NULL);

That would die with "redundant NOT NULL declarations", but current
master doesn't do that; and we don't do it for UNIQUE UNIQUE either.
So I modified the patch to make it ignore the dupe and create a single
constraint.  This (and rebasing to current master) are the only changes
in v15.

I have not changed the psql presentation, but I'll do as soon as we have
rough consensus on what to do.  To reiterate, the options are:

1. Don't show the constraint names.  This is what the current patch does

2. Show the constraint name in \d+ in the "nullable" column.
   I did this early on, to much booing.

3. Show the constraint name in \d++ (a new command) tabular output

4. Show the constraint name in the footer of \d+
   I also did this at some point; there are some +1s and some -1s.

5. Show the constraint name in the footer of \d++


Many thanks, Dean, for the discussion so far.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
Bob [Floyd] used to say that he was planning to get a Ph.D. by the "green
stamp method," namely by saving envelopes addressed to him as 'Dr. Floyd'.
After collecting 500 such letters, he mused, a university somewhere in
Arizona would probably grant him a degree.              (Don Knuth)