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= October 2 =

== Spider traps and DOS ==

[[Spider trap]] says that these traps may "cause a web crawler or search bot to make an infinite number of requests". Why would you do such a thing intentionally? Sure, it stops the problematic crawler/bot/etc., but wouldn't the effect be a denial-of-service attack, since you're being given an infinite number of requests? I see that there are other options (e.g. serving massive text files or refusing entry to something lacking the right cookie) that might simply crash the spider, but causing it to make infinite responses seems counterproductive unless I'm misunderstanding the whole concept. [[User:Nyttend backup|Nyttend backup]] ([[User talk:Nyttend backup|talk]]) 18:52, 2 October 2018 (UTC)
:These pages suggest that they are normally unintentional, https://www.portent.com/blog/seo/field-guide-to-spider-traps-an-seo-companion.htm https://yoast.com/spider-trap/ . This pages has a comment that one purpose is to stop email address harvesting. Ways to deliberately DOS the spider, would be to pause before returning content, and then dynamically generate page text without using disk storage. [[User:Graeme Bartlett|Graeme Bartlett]] ([[User talk:Graeme Bartlett|talk]]) 02:19, 3 October 2018 (UTC)
*A request-loop trap does not seem very intelligent to me, either, as these things go. However, your server will escape DOS if its ability to answer requests is higher than the spider's ability to make them; that does not necessarily mean you need more processing power or network capability. [[Denial-of-service_attack#Attack_techniques]] contains some inspiration, but for instance, the spider might have fallen in many traps in different sites (so the spider is DDoS'd), if the cost of making a request is higher than that of answering it (some DoS attacks work because a small query packet can request a large, bandwidth-guzzling reply), if you intentionally answer the spider's query very slowly (forcing them to maintain a low-throughput connection), etc.
:In case you also wonder why you would set out traps for spiders... Well, I have one on my website, but you might as well [https://www.neilgunton.com/doc/?doc_id=8580 read the original from whom I copied the idea] rather than my summary. My own spambot trap is a page generating many {{code|mailto:}} links to non-existent domains; there are links to that page by zero-width elements all over the website but is excluded in [[robots.txt]]. So the only ones who should read it, really, are non-robots.txt-compliant spiders, 99+% of which are malicious and 100% of which deserve at least what they get here. [[User:Tigraan|<span style="font-family:Tahoma;color:#008000;">Tigraan</span>]]<sup>[[User talk:Tigraan|<span title="Send me a silicium letter!" style="color:">Click here to contact me</span>]]</sup> 15:35, 3 October 2018 (UTC)


= October 3 =
= October 3 =
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::In this case, the "requests for predictions" is a lot like asking "will men ever walk on the moon?" The 2002 Data-Intensive Architecture (DIVA) system was the first 256-bit processor that I know of,[http://atrak.usc.edu/~changk/publications/esscirc02.pdf] the [[Transmeta Efficeon]] TM8300 256-bit Processor was released in 2004, and of course there is the [[AVX-512]] and the Nvidia Quadro FX5800. Of course you can always play a game on [[No True Scotsman]] if you want to deny that 265-bit processors exist... --[[User:Guy Macon|Guy Macon]] ([[User talk:Guy Macon|talk]]) 21:45, 3 October 2018 (UTC)
::In this case, the "requests for predictions" is a lot like asking "will men ever walk on the moon?" The 2002 Data-Intensive Architecture (DIVA) system was the first 256-bit processor that I know of,[http://atrak.usc.edu/~changk/publications/esscirc02.pdf] the [[Transmeta Efficeon]] TM8300 256-bit Processor was released in 2004, and of course there is the [[AVX-512]] and the Nvidia Quadro FX5800. Of course you can always play a game on [[No True Scotsman]] if you want to deny that 265-bit processors exist... --[[User:Guy Macon|Guy Macon]] ([[User talk:Guy Macon|talk]]) 21:45, 3 October 2018 (UTC)
:::I deny that '''265'''-bit processors exist. [[User:PrimeHunter|PrimeHunter]] ([[User talk:PrimeHunter|talk]]) 22:29, 3 October 2018 (UTC)
:::I deny that '''265'''-bit processors exist. [[User:PrimeHunter|PrimeHunter]] ([[User talk:PrimeHunter|talk]]) 22:29, 3 October 2018 (UTC)
::::There are some google resutls about it: [https://www.google.com/search?q=&quot;265-bit+processor&quot; "265-bit+processor"]. --[[User:Qlearn|Qlearn]] ([[User talk:Qlearn|talk]]) 11:13, 4 October 2018 (UTC)
::::There are some google resutls about it: [https://www.google.com/search?q=265-bit+processor "265-bit+processor"]. --[[User:Qlearn|Qlearn]] ([[User talk:Qlearn|talk]]) 11:13, 4 October 2018 (UTC)


:::::[[User:PrimeHunter|PrimeHunter]], are you claiming that the 256-bit Data-Intensive Architecture (DIVA) system and the Transmeta Efficeon TM8300 256-bit Processor didn't happen, or are you claiming that the sources that say that they were 256-bit processors were telling a lie? --[[User:Guy Macon|Guy Macon]] ([[User talk:Guy Macon|talk]]) 16:18, 4 October 2018 (UTC)
:::::[[User:PrimeHunter|PrimeHunter]], are you claiming that the 256-bit Data-Intensive Architecture (DIVA) system and the Transmeta Efficeon TM8300 256-bit Processor didn't happen, or are you claiming that the sources that say that they were 256-bit processors were telling a lie? --[[User:Guy Macon|Guy Macon]] ([[User talk:Guy Macon|talk]]) 16:18, 4 October 2018 (UTC)

Revision as of 02:41, 10 October 2018

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October 3

Space efficient index of a list

When you have several indexes, can you combine them to make them more efficient in terms of space?

If you wanted, for example, to access a list of names through 1st name or surname. Do you have to create necessarily one index for each? Intuitively, it makes sense to believe that you'll need 1 index for each way of accessing your information, but that wouldn't be a proof.

Speculative, I wonder whether there is some kind of data structure or hash value that could point to the right entry, when fed one or the other (1st name or surname). — Preceding unsigned comment added by Qlearn (talkcontribs) 00:49, 3 October 2018 (UTC)[reply]

I think the idea of having a general hash that could be generated by either of two seperate records is impossible. I expect it is a lot less efficient than having two indexes but of course you could use the LIKE function; name "John Smith" and search "WHERE NAME LIKE '%John%';" or "WHERE NAME LIKE '%smith%'"; -- Q Chris (talk) 11:09, 3 October 2018 (UTC)[reply]
You could always compress the string. The gain would be minimal and in the practice you don't want to trade processing speed for being stored efficiently. --Doroletho (talk) 13:00, 3 October 2018 (UTC)[reply]
You can implement the index as a trie, in which case you have automatic prefix sharing and performance independent of the number of indexed terms[*]. Then at the end node of each word have pointers to the various rows, each labeled with the target row. [*] Except that in theory the number of entries is exponentially bounded by the depth of the trie, and worst-case search is linear in that depth. --Stephan Schulz (talk) 15:47, 6 October 2018 (UTC)[reply]

Windows installer

Windows installer works great![1] --Guy Macon (talk) 07:11, 3 October 2018 (UTC)[reply]

Very funny. And what's your question? --Doroletho (talk) 11:00, 3 October 2018 (UTC)[reply]
If an ip user posted this they would be reverted for trolling. — Preceding unsigned comment added by 186.148.165.180 (talk) 11:46, 3 October 2018 (UTC)[reply]
I am sorry if that has been your experience. IPs should be treated the same as registered users, and I have seen editors get warned for treating IPs differently from registered editors -- and blocked for repeat offenses. All editors are required to obey WP:TPOC. A small amount of humor is allowed on Wikipedia outside of our actual articles:, see Wikipedia:Humor#Humor outside of articles. We have help for those who have trouble telling the difference between humor and trolling at meta:What is a troll?, along with an article on the concept at Internet troll. --Guy Macon (talk) 12:55, 3 October 2018 (UTC)[reply]
If you are one of those linux evangelists poking fun at Windows, I'd like to say that Windows is easier to install than Linux and on the top of that has improved several aspects in the last years. --Doroletho (talk) 13:07, 3 October 2018 (UTC)[reply]
Workers wearing safety vests and hard hats, on a job site
I am not a Linux evangelist poking fun at Windows. I use both and have found that Windows 10 is somewhat easier to install than Ubuntu and much easier to install than Slackware (Motto: "Slackware is user friendly. It's just picky about who its friends are"). Please don't try to read some hidden meaning into a lighthearted joke. --Guy Macon (talk) 13:44, 3 October 2018 (UTC)[reply]
but like what is your question even lol ~Helicopter Llama~ 14:54, 3 October 2018 (UTC)[reply]
I apologize. I somehow failed to realize that we are on Jeopardy!, where the rules say that you must must phrase your response in the form of question. (the presence of Alex Trebek should have clued me in).
When performing a Windows installation,[2] are hard hats required? Is there a problem with the average house having heavy things falling on your head that I was unaware of? And shouldn't the workers pictured also be wearing orange safety vests? --Guy Macon (talk) 15:31, 3 October 2018 (UTC)[reply]
Typical. Two people loudly insist that I make a comment in the form of a question, then neither of them attempts to actually answer the question... (note to the humor impaired; please attempt to understand the concept of "a joke".) --Guy Macon (talk) 16:03, 4 October 2018 (UTC)[reply]

Weird Excel table behaviour

There's a very convoluted story that I'm trying to avoid having to tell. :) The short version is that I have a series of defined tables, each on their own tab. They each do a series of calculations based on a complicated SUMIFS formula to help me present a variety of different bits of information, all drawn from a data dump (also on a separate tab). When I first created the formulas they naturally ended up with negative values. This was totally expected and the formulas are doing their thing properly. However, to make graphing easier to read, it was later decided to invert the values by multiplying them by -1. All good so far. However, when I go to add another week, the table "forgets" the new formula and the new row shows as negatives. So, assuming a scenario where each of the following weeks should show as "10", my table results in this:

Fiscal Week Cases credited
W01 10
W02 10
W03 -10

This forces me to fix each row manually by grabbing the previous week and dragging it down to the next row. It's very tedious. How can I gain access to see what Excel "thinks" the formula should be and change it? Even though every cell in every column shows as (complicated SUMIFS formula)*-1, subsequent new rows all forget to add the "*-1". I've drawn three weeks and a single column in here as an example, but in reality there are very many more so I would prefer not to have to redo all of them from scratch. Any help would be appreciated. Matt Deres (talk) 17:46, 3 October 2018 (UTC)[reply]

If the data is correct and the answer is "wrong" (= undesired) then the formula is the thing to fix. It sounds like you need to add to your formula one or both of these functions that are available in Excel:
SIGN Returns the sign (+1, -1 or 0) of a supplied number
ABS Returns the Absolute value of a supplied number
DroneB (talk) 19:01, 3 October 2018 (UTC)[reply]
Maybe I did not explain myself properly. If you were to examine the file right now, every single formula would be correct and giving the proper value. The problem develops when I add the next week in. In the example above, if I enter "W04" in the appropriate cell, Excel automatically extends the formulas in all the other columns - it's a standard function of a formally defined table. The problem is that the automatically created formulas are the old ones with negative values. I have to highlight the row above and manually drag down the updated formulas myself to correct it. Excel is somehow remembering the original formulas I used rather than simply extending the current ones. Matt Deres (talk) 12:36, 4 October 2018 (UTC)[reply]
I'm really not knowledgeable about Excel (or any spreadsheet), but have you tried to delete the row and then re-insert it with the new formula? --Stephan Schulz (talk) 09:48, 6 October 2018 (UTC)[reply]
Yes. No luck. Matt Deres (talk) 16:49, 7 October 2018 (UTC)[reply]
The answer by tjejojyj looks like a hackish workaround that might work [3] Nil Einne (talk) 01:45, 8 October 2018 (UTC)[reply]
While a bit different, it's also possible the answers here may work, especially the later ones [4] Nil Einne (talk) 01:49, 8 October 2018 (UTC)[reply]
Wow - those really look on point - thank you! I won't have access to the file again until next week, but I will definitely give those a try! Thanks again! Matt Deres (talk) 02:26, 9 October 2018 (UTC)[reply]

will there be 256-bit computers?

AWNSER THA QUASTON. — Preceding unsigned comment added by A Loaf Of Bread 2 (talkcontribs) 20:13, 3 October 2018 (UTC)[reply]

See the top of the page "We don't answer requests for opinions, predictions or debate." Dmcq (talk) 20:22, 3 October 2018 (UTC)[reply]
In this case, the "requests for predictions" is a lot like asking "will men ever walk on the moon?" The 2002 Data-Intensive Architecture (DIVA) system was the first 256-bit processor that I know of,[5] the Transmeta Efficeon TM8300 256-bit Processor was released in 2004, and of course there is the AVX-512 and the Nvidia Quadro FX5800. Of course you can always play a game on No True Scotsman if you want to deny that 265-bit processors exist... --Guy Macon (talk) 21:45, 3 October 2018 (UTC)[reply]
I deny that 265-bit processors exist. PrimeHunter (talk) 22:29, 3 October 2018 (UTC)[reply]
There are some google resutls about it: "265-bit+processor" "265-bit+processor". --Qlearn (talk) 11:13, 4 October 2018 (UTC)[reply]
PrimeHunter, are you claiming that the 256-bit Data-Intensive Architecture (DIVA) system and the Transmeta Efficeon TM8300 256-bit Processor didn't happen, or are you claiming that the sources that say that they were 256-bit processors were telling a lie? --Guy Macon (talk) 16:18, 4 October 2018 (UTC)[reply]
I bolded 265 (not 256) to make fun of a typo in your first post. Maybe it was too subtle. PrimeHunter (talk) 16:23, 4 October 2018 (UTC)[reply]
WHOOOSH! (that's the sound of a great joke going right over my head) Thanks! But is it true that there are no 265-bit processors? (Motto: "for when having more addresses than there are atoms in the universe just isn't enough".) I could make one if I had the chips -- see Bit slicing -- but I don't think that anyone is making a 1-bit bitslice processor any more. Hmmm. It might be possible to do it with a FPGA...
I assumed it was a subtle reference to Moon-landing deniers. 216.59.42.36 (talk) 17:36, 4 October 2018 (UTC)[reply]
At least for me, all of those seem to be probably copied typo references to some Mac Pro with a Xenon from 2013, I presume they meant 256 bit due to the Advanced Vector Extensions. Nil Einne (talk) 10:52, 5 October 2018 (UTC)[reply]
A main motivation behind larger bit numbers was the larger address space. However at 64-bit the address is practically unlimited. So, now there is no compelling reason to go for 128-bit or wider architectures, at least in consumer electronics. Ruslik_Zero 18:11, 4 October 2018 (UTC)[reply]
I don't think that we will ever need more than 64-bit addresses. But some of us could really use a larger data path and arithmetic. Bubba73 You talkin' to me? 18:18, 4 October 2018 (UTC)[reply]
Is this one big enough? [6] :) --Guy Macon (talk) 21:03, 4 October 2018 (UTC)[reply]
That's the good old Motorola MC14500B. Bubba73 You talkin' to me? 23:05, 4 October 2018 (UTC)[reply]
...A one-bit processor with 16 instructions and an ability -- depending on how you look at it -- to either address one bit of memory or to address any any amount of memory (for the simple reason that it requires an external circuit to handle memory addressing). It is about as simple as a microprocessor can be. Alas, I can't find anyone who still carries them -- even old stock.
http://www.ganssle.com/articles/quirkychips.html has a nice description, and https://www.youtube.com/watch?v=CIs9IuobcPE shows one that was built as a redstone circuit in Minecraft. --Guy Macon (talk) 10:23, 5 October 2018 (UTC)[reply]

October 4

Autocomplete/<TAB> in PowerShell when running Java programs

If I try to type the following using the autocomplete/<TAB> function:

java HelloWorld

PowerShell will autocomplete it to .\HelloWorld.class, which does not work.

Is there a way around this (at least the .\ as I can then remove the .class quite easily myself)? --Polyknot (talk) 19:07, 4 October 2018 (UTC)[reply]

Gmail old look

Since it looks like the switch to Gmail's classic appearance is no longer available, I wonder if there's any backdoor option to restore it. The grievances are there, but to no avail it seems. Brandmeistertalk 20:14, 4 October 2018 (UTC)[reply]

The page you linked to recommends (among other things) the css code you can get from https://userstyles.org/styles/159308/the-return-of-old-gmail-2010-design --Shantavira|feed me 15:04, 5 October 2018 (UTC)[reply]

WDR paper computer

I recently ran across our WDR paper computer article, and one line stood out:

"The operation is to register machines ajar , but is more to the approach of Shepherdson and Sturgis."

I have absolutely no idea what the above means.

I am pretty sure that it is a mangled translation from de:Know-how-Computer. The machine translation[7] is:

"The method of operation is based on register machines (the article of MC refers to Elmar Cohors-Fresenborg), but more in line with the approach of Shepherdson and Sturgis."

which is better, but I still don't understand the "the article of MC" language. Does anyone reading this understand German? If so can you give us a better translation? --Guy Macon (talk) 22:34, 4 October 2018 (UTC)[reply]

If you look earlier in the article, you'll see that mc is linked to de:mc (Zeitschrift). The corresponding article in English is MC die microcomputer-zeitschrift (magazine). In other words, the article in question was published in that magazine. --76.69.47.223 (talk) 04:37, 5 October 2018 (UTC)[reply]
@Guy Macon: Precisely the same translation was in the very first version of the article (Special:PermanentLink/848601532) but has been shortened soon by its author (Special:Diff/848602969). However, that doesn't explain the meaning, either. --CiaPan (talk) 05:43, 5 October 2018 (UTC)[reply]

Fixed the translation a bit (Special:Diff/862563532) based on Google's translation

--CiaPan (talk) 05:52, 5 October 2018 (UTC)[reply]

This was a TV series. This format would be on YouTube today. It is a predecessor of similar YouTube channel formats. On 24 July 2006, it was continued by the by the former hosts Wolfgang Rudolph and Wolfgang Back. --Hans Haase (有问题吗) 17:23, 6 October 2018 (UTC)[reply]

October 5

Java - error: integer number too large: 600851475143

As the title says, I get an error message when trying to assign that number to an int or even a long. How do I get around this? I'm not even sure if I should be getting this error as I don't think the number is that big. --Polyknot (talk) 11:49, 5 October 2018 (UTC)[reply]

Our article Integer (computer science) says in the table in the section 'Common integral data types' that Java int is 32 bits, hence its range is −2,147,483,648 to 2,147,483,647. You may try a 64-bit long for values up to 9,223,372,036,854,775,807. --CiaPan (talk) 11:57, 5 October 2018 (UTC)[reply]
As I said I've tried long as well and I still get the same error. --Polyknot (talk) 12:04, 5 October 2018 (UTC)[reply]
What error exactly do you get? And in what context? Is it about assigning the value to a variable, or may be about the value itself? Did you try to append L at the end of the constant, like this: 600851475143L, to indicate it is long? --CiaPan (talk) 12:31, 5 October 2018 (UTC)[reply]


Non-interactive "RPG"

I recall a parody non interactive "RPG" which worked on telnet (probably). Essentially you made a connection to the server and something like this happened:


...
>You hit the imp.
>The imp misses you.
>You defeat the imp.
>You gained 2xp.
>You are now level 2.
>You attack a brownie.
...

Essentially the longer you stayed connected, the higher level (and the more bored) you got. Naturally people had connected unattended telent sessions, some of them running for months or maybe years - there was a leader-board. If you disconnected, you had to restart from zero.

Anyone remember the name, location and know if it still exists?

All the best: Rich Farmbrough, 13:36, 5 October 2018 (UTC).[reply]

Maybe Progress Quest? [8] CodeTalker (talk) 13:57, 5 October 2018 (UTC)[reply]
That's the one! Progress Quest. Must play... All the best: Rich Farmbrough, 15:01, 5 October 2018 (UTC).[reply]
That looks like it is almost as fun as Desert Bus![9][10] --Guy Macon (talk) 16:35, 5 October 2018 (UTC)[reply]

October 9

Public post visibility on Facebook

Hi. If someone makes a public post on facebook, and their friends like/emoji that picture, do the friends of friends also see that picture in their feed? So, if X posted something, Y (who is friends with X) likes it, will Z (friends with Y, NOT friends with X) see that like in their feed? Sorry if this is confusing. Let me know if I can improve the question! Bottlecapmicrophone (talk) 16:57, 9 October 2018 (UTC)[reply]

It will vary with the settings X used when they posted, but yes, it is possible. For example, I sometimes see stuff in my timeline that refers to "Y likes/commented on this post..." It seems more common with comments than with likes, but they're there. Do you not have friends that like things? Matt Deres (talk) 21:32, 9 October 2018 (UTC)[reply]

Protection query

Okay, so the talk page is now protected for four days but the banner is not present, notwithstanding that the markup {{#ifeq:{{PROTECTIONLEVEL:edit}}|autoconfirmed|{{pp|small=yes}}}} is exactly the same as the last time the page was protected, when the banner did show. Why is this? On this desk (computing) the banner continues to show, as predicted here Special:Permalink/863214791#It's been October 9th for nearly half a day already. 86.152.81.16 (talk) 17:08, 9 October 2018 (UTC)[reply]

And as predicted the banner went away as soon as I edited. Actually the "edit" button did appear correctly when the protection came off. 86.152.81.16 (talk) 17:10, 9 October 2018 (UTC)[reply]