Object/Relational Mapping is the Vietnam of Computer Science
However, I came across coiner Ted Neward's blog post where he lays out the analogy in great detail.
Object/Relational Mapping is the Vietnam of Computer Science. It represents a quagmire which starts well, gets more complicated as time passes, and before long entraps its users in a commitment that has no clear demarcation point, no clear win conditions, and no clear exit strategy."
I highly recommend a full read. His list of six possible solutions is very interesting.
Jim Murphy: Object-Relational vs. Object-XML Mapping Layers
Coding Horror: Object-Relational Mapping is the Vietnam of Computer Science: "Personally, I think the only workable solution to the ORM problem is to pick one or the other: either abandon relational databases, or abandon objects. If you take the O or the R out of the equation, you no longer have a mapping problem."