ivanhoe (u/ivanhoe) - Readit News

ivanhoe commented on Homemade AI drone software finds people when search and rescue teams can't wired.com/story/this-home... · Posted by u/sohkamyung

krisoft · a year ago

Suprisingly your first idea is illegal in some states. For example it is illegal in Texas.

https://www.skysenderos.com/blogs/thermal-drone-deer-recover...

ivanhoe · a year ago

It'd be impossible to limit the use of drones to just recovery, some people would use them for tracking down the animals which is a horrible idea to allow.

ivanhoe commented on Common mistakes when using the metric system nayuki.io/page/common-mis... · Posted by u/stereoabuse

boxed · a year ago

I live in metric land (Sweden), and I have never seen "gr." for grams and honestly I would probably take a while to understand what it meant.

ivanhoe · a year ago

In ex-Yugoslavia countries using gr (usually without a dot) for grams used to be a fairly common thing. Last few decades as EU standardization takes place it's a lot rarer to see. Also in Croatia in everyday life people will far more often use decagrams (10g), shorten colloquially as 'deka', than grams - which leads to even more confusion because the SI abbreviation for decagrams is dag, not dg (which is decigram, 0.1g), and it's often mixed - even some primary school books had these typos.

ivanhoe commented on Soft Deletes with Ecto and PostgreSQL dashbit.co/blog/soft-dele... · Posted by u/todsacerdoti

lelanthran · a year ago

> What goes wrong with the classic soft-delete approach? The one where every table has a boolean is_deleted column and hopefully the deleting code updates the correct subgraph of records at the same time?

> It typically rots as you expand your model and add features. It's not clear what significance different tables have, and you you can't "restore" things with any reliability or safety. That may be because of relational/index conflicts, or because you don't have enough information about how it was originally deleted to actually "restore" something that is both correct and useful, or because there are actually 3 different kinds of restoration schemes/scopes but current problem calls for a fourth.

The long and short of soft deletes is that it breaks my data's correctness guarantees WRT referential integrity: i.e. I 'delete' a record while there are still references to it, and the RDBMS cannot even warn me, much less stop me!

If I wanted broken data, I'd use a NoSQL DB, or flat files even.

ivanhoe · a year ago

Also makes UNIQUE indices much harder to use. You can't just delete and later re-insert the same data, you need to "undelete" it instead, but that can actually mess up the chronology of the data, so then you need a separate table to track dates... and things just get over-engineered quickly...

ivanhoe commented on Soft Deletes with Ecto and PostgreSQL dashbit.co/blog/soft-dele... · Posted by u/todsacerdoti

Terr_ · a year ago

Soft-deletes in relational databases are almost always a mistake. Most use-cases are actually business rules/processes which need to be clearly examined and done more explicitly and contextually, at least if you ever want to restore anything.

For example, you don't soft-delete a customer row, you "deactivate" a customer, and change logic that looks at customer-related entities to fit that. The "Customers" page that shouldn't show those anymore gets retitled to "Active Customers." Later there will be either process for reactivating customers or for using a permanently deactivated customer as a template for a new one.

What goes wrong with the classic soft-delete approach? The one where every table has a boolean is_deleted column and hopefully the deleting code updates the correct subgraph of records at the same time?

It typically rots as you expand your model and add features. It's not clear what significance different tables have, and you you can't "restore" things with any reliability or safety. That may be because of relational/index conflicts, or because you don't have enough information about how it was originally deleted to actually "restore" something that is both correct and useful, or because there are actually 3 different kinds of restoration schemes/scopes but current problem calls for a fourth.

ivanhoe · a year ago

> For example, you don't soft-delete a customer row, you "deactivate" a customer

I'm all for naming things more precise, but functionally speaking at that point it's really just semantics, you still end up with some DB column acting as a flag, and from then on you need to take it into account in every single query that touches that table in the whole app. Since most modern ORMs know how to handle soft-delete internally, it's far easier to just stick to the defaults and use `deleted_at` if you really need a way to keep the records around. And you often need, for the referential integrity of the historical data.

ivanhoe commented on Vikings in al-Andalus and the Maghreb alandalusylahistoria.com/... · Posted by u/Bluestein

rdtsc · a year ago

> traders, as they've created the trading (and also slave)

So much so that the word “slave” in Greek and other languages comes from “Slavs”?

ivanhoe · a year ago

Yes, but I believe it was Latin, not Greek (Constantinople was a capitol of Easter Roman Empire, and they used both Latin and Greek). Latin term Sclavi that meant Slavs started to be used for slave servants, because there was so many of them.

ivanhoe commented on Vikings in al-Andalus and the Maghreb alandalusylahistoria.com/... · Posted by u/Bluestein

Bluestein · a year ago

> There was no "buffer" that stopped them, they've stopped eventually because their Great Khan died.

Basically unstoppable, eh? So, basically, an "accident" of history they did not take over the Mediterranean ...

ivanhoe · a year ago

Well, they were basically a highly-mobile light cavalry/archers combination, so while they progressed very fast they were not spending much time sieging heavily fortified cities or going into mountains and other hard to cross terrains. Also it took Europeans a while to learn how to fight them efficiently, but eventually they did figure out that European heavy cavalry is a good match for them. So it's not they were "unstoppable", they simply avoided hard targets, and pillaged the villages and other less defended areas, and moved quickly through disorganized European kingdoms fighting each other.

ivanhoe commented on Vikings in al-Andalus and the Maghreb alandalusylahistoria.com/... · Posted by u/Bluestein

Bluestein · a year ago

> the Mongols came and destroyed Kiev, murdering just about everyone

I wonder to what degree - if any - these poor people served as a "buffer" against the Mongols, saving Europe from the slaughter ...

ivanhoe · a year ago

> these poor people served as a "buffer" against the Mongols, saving Europe from the slaughter ...

You mean saving Western Europe :)

Mongols ran over (and did a lot of slaughter in) the most of Eastern and Central Europe, including Poland, Czechia, parts of todays Germany, Hungary, Bulgaria, Croatia and Austria. There was no "buffer" that stopped them, they've stopped eventually because their Great Khan died. As the leadership broke down and fights for power arose, they've been forced to return back home.

ivanhoe commented on Vikings in al-Andalus and the Maghreb alandalusylahistoria.com/... · Posted by u/Bluestein

LarsDu88 · a year ago

Rus is what these people called themselves. They were folks lured to that part of the Mediterranean by promise of work in the Byzantine military as Varangian Guards.

A subset of these Norsemen sailed up the Dniper to what is today Kiev and setup Kievan Rus. They ruled over and assimilated the the Slavic, Bulgar, and Turkic peoples of the area. In the Middle Ages, the Mongols came and destroyed Kiev, murdering just about everyone inside, leading to fragmentation into multiple polities like Moscow, the Novgorod Republic, and Vladimir.

The Rus ethnonym lives on in the name of the Russians, Rusyns, Ruthenians, Belarussians, and others!

ivanhoe · a year ago

You reversed the timeline a bit.

Varangians came primarily from todays Sweden, and were initially going inland into the today's Estonia, Belarus and Russia from north, from the Gulf of Finland, using rivers. The group of them called Rus under the leadership of Rurik created Novgorod in 862. About 20 years later they've also conquered Kiev (some 900km more to the south). They were initially raiders, but over time they've conquered the local Slavs, established their rule and became very important traders, as they've created the trading (and also slave) routes all across the continent from the Baltic in the North down to the Black Sea - using huge rivers like Volga and Dneper - trading in south with Byzantin empire and Abbaside Caliphate. It was one of the main trading routes between West/North Europe and Arab world of that age.

And as their presence grown stronger, the Rus started more frequently raiding the Byzantin Empire, sacking even the big Constantinople a few times. To stop these attacks, in 10th century the Byzantines did the same move as king Charles the Simple did in Francia with Normans, they gave Varangian leaders some titles and employed them all as a royal guard. Problem solved.

And then, as you've said, the viking era was over, and they assimilated into the Slavic population (just like Bulgars and others did).

Another interesting note, the Rus ethnonym also got into many Slavic languages as a word for fair blonde or reddish-blonde hair ("русая" in Russian, "rusa" in Serbian/Croatian, etc.). In Serbian 'rus' was historically used in folk language with a meaning 'red', for instance for skin rush, names of some herbs, etc.

ivanhoe commented on Horses may have been domesticated twice sciencenews.org/article/h... · Posted by u/diodorus

seabass-labrax · a year ago

Your comment made me wonder if anyone did actually organize a horse fight, and it turns out that the answer is yes - in Iceland during the Viking Age[1]. Thankfully, people seem to have found more wholesome activities to do with their horses now, including teaching them to type[2].

[1]: https://www.medievalists.net/2016/08/horse-fights-the-brutal...

[2]: https://www.visiticeland.com/outhorse-your-email/

ivanhoe · a year ago

Thank you for this, had no idea :)

ivanhoe commented on Waymo One is now open to everyone in San Francisco waymo.com/blog/2024/06/wa... · Posted by u/ra7

tmpz22 · a year ago

> These cars are literally unsupervised.

Unsupervised in what sense? There's internal cameras that are periodically checked. Weight and seatbelt sensors that give alerts if a passenger is or puts objects in the drivers seat, or if too many individuals get in the car.

I'd be shocked if a similar or greater level of observability doesn't also exist outside the car.

ivanhoe · a year ago

How do you remotely detect if car stinks or not?