Collection of insane and fun facts about SQLite
Collection of insane and fun facts about SQLite
avi.im
Collection of insane and fun facts about SQLite - blag
37 comments
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There are over 600 lines of test code for every line of code in SQLite
Holy mother of god
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And they still find new bugs
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A limitation of testing is that you can only write tests for cases that you can think of, and cases you can think of ways to write tests for.
It's still valuable despite this limitation, of course.
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You can write shit tests. Finding new bugs doesn't surprise me. Putting that much effort in does, but 600:1? That's some serious red flags there. There are only so many variables in a single line of code. How many unhappy paths can there be for a single line?
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I get it...I've never been the maintainer of a codebase that's deployed on trillions of devices, and backwards compatibility is something to be taken seriously and responsibly when you're that prolific. I do not begrudge SQLite or any large projects when they make decisions in service to that.
However
It always makes me feel oddly icky when known bugs (particularly of the footgun variety) become the new standard that the project intentionally upholds.
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I'm so confused that the same people can say "why does everyone get their undies in a bunch that we happily accept putting arbitrary data in columns regardless of type, that's good, it's flexible, but fine, we'll put in a 'strict' keyword if you really want column types to mean something" and also "every other SQL says 1=='1' but this is madness, strings aren't integers, what is everyone else thinking?!"
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Strongly typed is orthogonal to strictly typed, so these two properties alone are not contradictory.
However, it is a bit unsettling that, if a column has an INTEGER type affinity, and you try to put a string in it, then the string is implicitly converted to an integer if it represents an integer and just stored silently as-is otherwise.
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It's not on trillions of devices, just billions. But e.g. a typical android phone has 1000s of sqlite db's for different purposes.
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You’re right, that’s a distinction I failed to make
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I had no idea the maintainers of sqlite were religious fanatics.
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As long as they don't go on a holy crusade or forcefully evangelize the entire world by genocide I wouldn't call them fanatics.
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Yeah, the code of ethics thing shocked me as well, but it's really important to remember that it's not something they expect users to follow, it's something the devs are saying they'll follow. So it's not too bad in my opinion.
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Why do we even need a server? Why can’t I pull this directly off the disk drive? That way if the computer is healthy enough, it can run our application at all, we don’t have dependencies that can fail and cause us to fail, and I looked around and there were no SQL database engines that would do that, and one of the guys I was working with says, “Richard, why don’t you just write one?” “Okay, I’ll give it a try.” I didn’t do that right away, but later on, it was a funding hiatus. This was back in 2000, and if I recall correctly, Newt Gingrich and Bill Clinton were having a fight of some sort, so all government contracts got shut down, so I was out of work for a few months, and I thought, “Well, I’ll just write that database engine now.”
Gee, thanks Newt Gingrich and Bill Clinton?! Government shutdown leads to actual production of value for everyone instead of just making a better military vessel.
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another one not mentioned there: sqlite is really tiny: (from https://sqlite.org/faq.html#q18 )
The default configuration of SQLite only supports case-insensitive comparisons of ASCII characters. The reason for this is that doing full Unicode case-insensitive comparisons and case conversions requires tables and logic that would nearly double the size of the SQLite library.
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Their commitment to backwards compatibility, to the point of keeping a known bug that allows primary keys to be null, is both amazing and "wtf".
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You can do backwards compatibility and make breaking changes to fix bugs. All you need is an opt-in "target version". CMake and Android are good examples of this.
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So nerdy, so good
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Here's a fun fact not noted in the article: Temporary files in sqlite are named etilqs_something in order to prevent people from contacting the sqlite developers for support when other applications (specifically, McAfee) have decided dump and not prune temp files.
Source: https://github.com/sqlite/sqlite/blob/95f6df5b8d55e67d1e34d2bff217305a2f21b1fb/src/os.h#L57
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Hmm, well... I have never murdered anyone, not even once! Is that good enough for their Code of Ethics?
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This article is written as though it is targeting FOSS newbie or something -- a weird mix of jargon and simple language designed to overawe someone.
Their VCS is at least as interesting as SQLite :)
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#17 mentions strict and links to its documentation.
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37 comments