My C++ brain must be getting too old -- head is swimming :( From all the talk, these must be very useful, but I don't understand why? Why not just use an object?
Many a brain have pondered the same question since the beginning of time.
For instance, you can meditate over the following koan:
-----
The venerable master Qc Na was walking with his student, Anton.
Hoping to prompt the master into a discussion, Anton said "Master, I have heard that objects are a very good thing - is this true?" Qc Na looked pityingly at his student and replied, "Foolish pupil - objects are merely a poor man's
closures."
Chastised, Anton took his leave from his master and returned to his cell, intent on studying closures. He carefully read the entire "Lambda: The Ultimate..." series of papers and its cousins, and implemented a small Scheme interpreter with a closure-based object system. He learned much, and looked forward to informing his master of his progress.
On his next walk with Qc Na, Anton attempted to impress his master by saying "Master, I have diligently studied the matter, and now understand that objects are truly a poor man's closures." Qc Na responded by hitting Anton with his stick, saying "When will you learn? Closures are a poor man's object." At that moment, Anton became enlightened.
Because there's no need to burden ourselves (and, perhaps more importantly, the people who'll have to maintain the code after us) with a whack of boilerplate for a fairly simple function.
(Also, you can use enclosed variables inside of map/fold constructs, which would be hard to express via objects.)
This surprises me. Though I've used it with great success for several small projects, my only experience with SQLite on anything remotely large was a Rails app with maybe a million records in the DB. Over time, performance became very slow and switching to MySQL made a world of difference.
At the time, I attributed it to SQLite, but now I'm wondering if it was Rails or (more likely) my inexperience at optimizing performance of the app at that time.
It was about three years ago, though, so I am sure performance in SQLite (and Rails, too, for that matter) has also likely improved a lot during that time.
In SQLite, autocommit is on, so if you weren't explicitly setting your transactions, you might have been commit after each update. Also, the standard disk cache is 2MB, so if you think your DB should have more memory than that, up it with default_cache_size.
Ah, I wasn't, so that combined with pilif's comments regarding the file being locked for writes would make a lot of sense as to why things were slowing down.
Write operations to a SQLite file lock the whole file. It's possible that your rails app had enough users doing enough writes so that the processes had to constantly wait.
As long as you are the only user, performance should be constant regardless of file size (minus fragmentation issues)
Implementing a B-tree is not easy but no black magic either (I did it for my diploma theses). Same for a hash join. And these two things are really all you need to have reasonable performance for simple selects and joins on tables of almost any size.
But if your queries get more complex, the query execution plan starts to make a huge difference - and a query optimizer is black magic, as anyone who's wrestled with Oracle's can attest. I doubt SQLite can compete in that area.
I rather see it as highlighting a weakness in the system. Arresting someone on suspicion without evidence tying the human to the twitter account and to the actual crime is a sad state of affairs. People should be made aware that this kind of thing cam happen with little recourse for the mistakes of the police.
Wouldn't the analog(ue) be framing? Just because one can frame people (on-line or IRL) doesn't mean the system is flawed. It just means there are people out there willing to have someone else be the fall-person as an end, or as a distraction to buy time in order to escape (or allow the trail of evidence to tail off/go cold.)
I don't know precisely how it works in Scotland, but presumably they had evidence sufficient to obtain a warrant for the arrest. Are you really saying the police should have to prove guilt before arresting suspects?
The police (here in Scotland or pretty much anywhere) can arrest someone on suspicion of something with pretty minimal evidence, you don't need a warrant but once you have arrested them you then have to either charge them or release them within a relatively short space of time (our rather draconian anti-terror laws which mean they can be held for weeks without charge wouldn't apply here).
It makes no sense for them to arrest him without evidence. The two options for who arrested him are local or national police.
If it were the local police why would local police on a sparsely populated island with little crime go and arrest someone and accuse them of being a hacker with no evidence knowing that he'd be out in a day? It makes no sense to do so and if you did do it you certainly wouldn't go public with the arrest knowing you had no evidence.
On the other hand if you're national police working in cyber crime out of London, to make the arrest you've got to convince someone to pay to fly two officers six hundred miles north and them and the suspect back. Given that UK police are being asked to make massive budget cuts and are under significant scrutiny (particularly the Met who would likely be heading this) because of the phone hacking, that trip isn't getting signed off without someone convincing a senior officer that there was something to it.
So the chances of there being no evidence is basically nil. The evidence they have may be misinformation, or they may have misinterpreted it, but they will have believed that this guy was involved.
