Sooner or later, every database is going to need a schema change, usually to coincide with a software upgrade. Sometimes it’s simple, just adding a little more data. Sometimes it’s not so simple and things go wrong and you need to make them right. Here’s my current best idea how to go about minimizing pain, assuming we have some software version X that we’re upgrading to version X+1, and that the installer or upgrade tool will need to upgrade the database from schema Y to schema Y+1. I’ve used plans like this pretty successfully, but came back to the idea after thinking about the statistical component of the problem more recently.

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As allowed and/or required by the C standard, OpenBSD provides integer types in a variety of sizes. Usually you don’t need to know the exact size of a type, but it’s helpful to know. Portable code, of course, should not rely on these assumptions. There is also endianness, but that’s different.

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Here’s an analogy I’ve been contemplating for explaining the unknown unknowns concept. In particular, the assumption that one’s own experience is complete. They’re like a kid who thinks he’s a deep sea diver because his ears popped when he swam to the bottom of the deep end. The analogy is particularly suited to How bad can it be? types of conversations.

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I leave the give away Acer at home, figuring I would have no need for it and a week later find myself at the store buying another laptop. I had originally figured the T60 would be a good machine for doing all my classwork, but slowly lost interest in that idea after thinking about carrying it to class. It’s a little heavy and cumbersome, true, but I think the real deterrent is that I like it too much and didn’t want to force it out onto the mean streets.

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Finishing up the aftermath of moving again reminded me of the virtual moving idea. You find someone leaving wherever you’re going to who, in turn, is moving to wherever you’re leaving. (Possibly of a chain of such people, but it gets complicated fast.) The two parties pick a date and swap apartments, contents included. My TV is your TV, your TV is mine. Maybe a little cash changes hands to balance out gross inequality. But it saves both parties a lot of time, labor, and expense.

The idea originated when I realized it would cost more to ship my belongings across the country than they were worth. Selling everything, moving a wad of cash, then buying equivalent stuff worked out well, but there’s a lot of friction because you end up selling low and buying high. If you could just get matched up with someone going the other way, you could agree on much more equitable prices and not even bother with craigslist.

Installed Ubuntu on an HP Mini 110 I had lying around, figuring it’d be a good cheap system to take on the road I wouldn’t mind losing. The short version is that everything mostly works, except the stuff that doesn’t. I’m more used to OpenBSD, but I’m trying to separate difficulties that come from familiarity issues and real problems.

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I just installed Ubuntu recently and it gave me the opportunity to reflect on what makes a good vs bad operating system installer. The short version is I don’t really like the way Ubuntu’s installer is designed because the task it is performing isn’t really installing an operating system.

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Currently, the web server for tedunangst.com (without www.) is set up to redirect all requests to www.tedunangst.com/. I could have mirrored the content, or redirected to the full URL, but instead everything goes to the top page. While it’s a little less convenient for anyone stumbling upon such links, in the long run I think it’s beneficial.

The long term goal is to only have one canonical website. I don’t want the same pages available at slightly different addresses. So mirroring is out. Redirecting is possible, but links without the www part will continue to proliferate if they work. The dumb redirect gives people enough of a hint on how to find the content they came for and offers a stronger disincentive to continued sharing of the broken link.

Update: Now there’s no A record at all. Too many stupid bots trying to crawl the site without www.

A few years ago I added a new function to OpenBSD libc, strtonum, to solve yet again the problem of converting a string into a number. In OpenBSD, we happen to like the function, but other projects have made various objections. The man page gives a brief explanation of the function, but it’s not a full history. I’ll try to clear the air by explaining strtonum’s rationale and responding to its criticisms.

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Two movies and one novel. To prep for watching the new movie version, I first watched the older movie. I had heard the new one was more accurate in some way, but after watching both I decided to read the book as well to make my own determination.

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