Hacker News Reader

Comment by xradionut | Hacker News Reader

Very few experienced programmers will have these beliefs. Addresses are the most fucked up personal information that we have to deal with. Names run a close second.

Over beers a few of my mates came up with a system like DNS to map a mailing domain for an individual/organization to a physical location. But after much discussion we decided it was just easier to let the geo-challenged to lease postal boxes with saner locations.

View on HN

> Very few experienced programmers will have these beliefs.

You're over-generalizing your personal experience: I've run into quite a few experienced programmers who just haven't spent enough time working on geo code to understand how treacherous it can be, particularly if their past work hasn't been sufficiently international. This is particularly bad with low-level / overly-academic developers who think the problem is that previous attempts failed because they didn't model addresses sufficiently rigorously.

I'd say that in the US Social Security Numbers run neck-and-neck with names for causing problems, though the data is less screwed up. The problem is that they look simple, unique, and universal so they're an obvious primary key... but only the first of those is close enough for most uses. Duplicate SSNs have been issued often enough that I've run into multiple collisions in a single production DB (and confusing two people on electronic home arrest can be pretty bad). Even more common are people who simply don't have one - religious objectors, non-citizens who haven't acquired them (though some have them), etc. The net result is that people keep using them as primary keys, as join keys, and as unique constraints and then get bitten hard.

> Over beers a few of my mates came up with a system like DNS to map a mailing domain for an individual/organization to a physical location.

Isn't that what ZIP codes should have been?

In the UK my postcode is limited to not many addresses. (Mine is 10, but they can be more.) The Post Office database is widely used. It's not always particularly accurate. While there's no official database of addresses the Post Office database is pretty close.

In France postcodes usually span several towns, or one medium city, and only larger cities have several postcodes (three for my 300 000 inhabitants city, for example).

They are not very precise, which is to be expected since there are only about 100000 possible postcodes in our scheme.

The US used to have five-digit postcodes, now has nine-digit ones, but laypeople mostly ignore the extra four digits. Singapore used to have two-digit codes, then upgrade to four, then to six. Maybe French postcodes will grow another digit or two someday.

The U.S. system is nice in that most people only even need 5 digits. The USPS reduces fees for their large customers that use all 9 digits, so they still end up with the majority of their mail being very specific, while those just sending a letter to a relative can just use the 5-digit code and let the destination post office take care of re-sorting it before delivery.

This really makes me wonder about the practice of "anonymizing" data down to birthday / sex / zip

It's not anonymous enough. I pointed out that this fact was buried in a story a while ago on HN [1]; it had a grand total of 6 upvotes and mine was the only comment.

Moral: The best content doesn't always stay on the front page for any length of time, you should check out /newest once in a while too.

[1] https://news.ycombinator.com/item?id=5609470

I saw that; I was aware that such data could be fairly reliably deanonymized. But with a country norm where zip codes frequently contain 10 people, who would ever imagine that just zip, with birthday / sex stripped, would be even slightly anonymous?

Reply on news.ycombinator.com