[darksaints]

You, probably like myself, took way too long to discover them because they have a fairly niche usage and are probably Postgres' least appropriately documented feature. It makes it hard to imagine the ways that it can be used. We should probably do something about that.

[ramraj07]

I read the second description in the manual and amazed it exists. I can totally see use cases where you want "almost unique" constraints (same name, date of birth too close??)