If given the choice between do it half-assed but quickly and do it right but using how ever much time is required to arrive there, the PostgreSQL team always choses the latter approach.
This conservatism works well for me considering we're talking about a database here.
One of the contributors has written an interesting article explaining why upsert is difficult to get right (if by "right" you want it to complete reasonably quickly and without any chance of corrupting your data):
This conservatism works well for me considering we're talking about a database here.
One of the contributors has written an interesting article explaining why upsert is difficult to get right (if by "right" you want it to complete reasonably quickly and without any chance of corrupting your data):
http://www.depesz.com/2012/06/10/why-is-upsert-so-complicate...