Comment 10 for bug 1835953

Thanks for this patch, Jason -- particularly the tests and docs! On first glance, it looks good. My only concern is that adding the NOT NULL constraint to such a large table as action.circulation in the upgrade script could cause a long ACCESS EXCLUSIVE lock.

I was trying to find some good documentation on the topic. This page from squawk seems okay: https://squawkhq.com/docs/adding-not-nullable-field

They note that on postgres 11 and higher, if you supply a default value, it doesn't have to do a full table scan, which should speed up the amount of time it hangs on to that lock. They also suggest a workaround of the ADD CONSTRAINT... VALIDATE CONSTRAINT dance.