Seamus Abshere <seamus(at)abshere(dot)net> writes:
> I hesitate to share my query and indexes because it makes this question
> seem more esoteric than I think it really is... but here we go.
> * Version 9.6.3.
> * I don't have any foreign key constraints.
> * I don't use serializable.
> * My update query is very careful to stay in an id range. [1]
> * I do have some exotic indexes [2]. gist, gin, postgis, fillfactor...
I'd bet on the last one, especially since you found that the problem
was a page-level lock. Did you look to see which relation the page
lock was in?
regards, tom lane