Mark Hills <mark@xxxxxxxx> writes: > On Wed, 8 Feb 2023, Laurenz Albe wrote: >> It takes 30 seconds to schan the table and determine that all existing >> rows satisky the constraint. > But there's no existing data (note this is adding column, not constraint) > Existing rows are guaranteed to satisfy the domain check, because the > domain check is guaranteed to be immutable (per [1] in my original mail) immutable != "will accept null". There could be some more optimizations here, perhaps, but there aren't. regards, tom lane
