If you are not doing data migration, after n revisions to the data management code, each record can be in any of 2^n states, depending on which code revisions d

If you are not doing data migration, after n revisions to the data management code, each record can be in any of 2^n states, depending on which code revisions did or did not modify it. How many revisions can you make before your code can no longer handle some of your older data? I'd say days' worth, not months, because you're trying to iterate a lot faster than we did. And the odds of a complete rewrite understanding all your old data are even worse. If you are doing data migration, you necessarily have an old and new schema in your head. At that point you're just refusing to write it down and let the tools tell you whether the code agrees with you.