Last time I looked into this, a big thing stopping it from happening was that the SQL standard for this kind of sucks and there is no consensus for a better syn

Last time I looked into this, a big thing stopping it from happening was that the SQL standard for this kind of sucks and there is no consensus for a better syntax among the databases that implement it. I would also love to see it, and I'd be amazed if it were as technically complex as, say, materialized views.