There are two sorts of standards in the world; let us call them forcedstandards and voluntary standards.

With a forced standard, someone makes you adhere to the standard. If youdon't, you can't get your product licensed or certified or whatever, andyou can't sell it or give it away or do whatever you want to do withit. Sometimes this is forced because of legislation, and sometimes thisis just forced through the marketplace; no one will buy your productif it is

In the process of writing the last entry , I finally realized something about SQLforeign keys. Specifically, about what you could call their lifetime, byanalogy to object lifetimes in garbage collected languages.

Everyone knows (hopefully) that you don't want to have long-livedobjects hold references to what should be short-lived objects. In a GC'denvironment such (strong) references convert the short-lived objectsinto long-lived ones; they can't be GC'd before the long