Do you know what the Halloween Problem is? I learned about it first in 1997 when learning SQL from Don Chamberlin.
Learning from Don meant I implemented inline SQL Function support. He designed and implemented the quality assurance breaking within minutes what I believed to be bullet proof design. "Learning from failure" is how you call that I think. The story of the Halloween Problem is nicely recounted on Wikipedia . In it's essence it involves: A scan operation over a table or index An action within that scan which changes a... [More]