On 2024-Apr-11, jian he wrote: > now I figured out that > dropping a column of primary key columns will not change other key > columns' "not null" property. > dropping the primary key associated constraint will make all key > columns "not null" property disappear.
Well, I think you were right that we should try to handle the situation of unmarking attnotnull as much as possible, to decrease the chances that the problematic situation occurs. That means, we can use the earlier code to handle DROP COLUMN when it causes a PK to be dropped -- even though we still need to handle the situation of an attnotnull flag set with no pg_constraint row. I mean, we still have to handle DROP DOMAIN correctly (and there might be other cases that I haven't thought about) ... but surely this is a much less common situation than the one you reported. So I'll merge everything and post an updated patch. -- Álvaro Herrera 48°01'N 7°57'E — 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)
