You presented some made up limitation as fact; you said it CANNOT be extended. Now you're trying to support your argument further by saying it's EASIER elsewhere. You should have just said that. I hate it when the opinionated use made up facts to justify their opinions. Please don't do that.

All these database engines are pretty weak. I prefer to use SAS for this kind of thing (including seeing stuff from previous/future rows.) It may not be client/server, but it is astoundingly fast for large datasets nonetheless.