The Nineteenth Byte

Jo King

12:02 AM

Does anyone know how my SQL query can take longer the less data I put into it? It's driving me mad

Nathan Merrill

when timing sql statements, you should always run explain

it gives you how the query is actually being executed

Jo King

I did! It still doesn't make any sense

quartata

what does it say

Jo King

Nothing out of the ordinary. Most of the columns are indexed, so the row count is ~17000

It takes 30 seconds to do 1 years worth of data, but takes 2 seconds to do 3 years worth of data. :(

Zacharý

done

Size 24 submission ...

Anonymous

12:26 AM

@JoKing Try running the queries without caching and check the times

Anonymous

In MySQL it's SELECT SQL_NO_CACHE ...

New Main Posts

0

Q: Exact Partial Sum of Harmonic Series

Challenge Given a positive integer N, output the sum of the first N reciprocals as an exact fraction, which is represented as a pair of integers in a consistent order representing numerator and denominator. Rules Output must be exact. Output should be as a pair of integers in a consistent ord...

Jo King

12:49 AM

@Mego It already had no-cache

Anonymous

Hmm... Even with really bad indexing, it shouldn't take 15x to process 1/3 of the data

Jo King

Yeah, we're changing the query anyway, but we can't figure out why it was behaving like that. Maybe it's some weird behaviour with a left join or something

Anonymous

I wouldn't think that the parameters would drastically change the execution plan, but you never know :P

Riker

1:08 AM

@quartata that steam (blackberry) name was from a long discussion about cinderblocks with my sister

specifically how much these ones on a construction site looked like oddly shaped tums

like the antacid pill

quote, I posted this in the discord as well:

> "[...] I like the strawberry flavored ones, and even the cherry ones, but not the blackberry flavored ones."
> "riker, you like blackblerry cinderblocks?"
> "no, tums"

quartata

I didn't know people were supposed to like tums

quartata

2:12 AM

i am writing the worst C of all time and none of you can stop me,

Zacharý

2:25 AM

@quartata Example?

quartata

void update_tweet_list(void)
{
    PGresult *result = PQexec(conn, "SELECT link from latestImage LIMIT 1;");

    if (PQntuples(result) > 0)
    {
        int urlLength = PQgetlength(result, 0, 0);

        atomic_flag_test_and_set(&inImageUpdate);
        while (atomic_flag_test_and_set(&inImageRequest)) usleep(0);
        atomic_flag_clear(&inImageRequest);

        if (!latestImage.p)
        {
            latestImage.p = malloc(urlLength);
        }
        else if (urlLength > latestImage.len)

this is probably the least deliberately-bad function of it

i decline to show the part where i deliberately globally store a pointer to a buffer allocated on the stack

(and yes it still works, the lifetimes line up)

the perfect complement to tweets that don't work is code that just works..

consider this your sneak peek

and yes, i dont care that PQgetvalue is in network order. so what. i dont read it anyways,

and yes, i dont care that my SQL is incoherently cased. take that trolls. the ultimate bamboozle.

from looks better lower-case, it's true

Zacharý

Doesn't look bad to me...

quartata

its pretty bad

of course theres some context missing but

Anonymous

3:05 AM

What exactly are you trying to do?

New Main Posts

3:44 AM

0

Q: Compose two Brainfuck programs

Given 2 brainfuck code snippets A and B, output some brainfuck code C which has the same behavior as running B with the input of As result. Note that C must work for any input that match the following assumptions, as if it were given to A. You can assume: Finite input. both A and B halt. EOF i...

code-golf code-generation brainfuck

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

Minimal Centrosymmetrization matrix code-golf array-manipulation Topically related. Objective: Given a matrix of positive integers \$M\$, output the smallest centrosymmetric matrix which contains \$M\$. A centrosymmetric matrix is a square matrix that is symmetric about its center. This means...

New Meta Posts

7:54 AM

0

Q: atomic-code-golf tag wiki is misleading

Today I corrected someone who thought that scoring by counting the number of calls to a given function at runtime is atomic-code-golf. Said person pointed me at a quote from the tag wiki: Atomic code golf asks you to solve a task using only a limited set of operations, with as few of these op...

discussion tags tag-wikis

gnu-nobody

8:44 AM

hello, back to ppcg after a looong break and a different username

New Sandboxed Posts

9:06 AM

0

A: Sandbox for Proposed Challenges

Drawing a convex polyiamond A subtask of Drawing convex polyiamonds. A polyiamond is a polygon made from equilateral triangles. For example: (example in ASCII art) * / \ *---* Or: *---* / \ / \ *---*---* \ / * (with lines drawn between the triangles for clarity) While the first ...

New Sandboxed Posts

10:12 AM

0

A: Sandbox for Proposed Challenges

Quiet QR Your mission, should you choose to accept it is to infiltrate the top secret HQ of the Big Bad Evil Guy (TM) and extract information on their latest evil scheme saved in the file Plan.txt. The target PC is isolated from any and all network connections, and you can't physically connec...

Adám

@gnu-nobody Who were you?

gnu-nobody

wait i thought i changed my username

New Main Posts

11:20 AM

-1

Q: Regarding threads in c++

Write a program that takes two numbers as input. First number m should be between range 0 - 10000 and second number n should be greater than one and less than m. Divide the range between n diﬀerent threads such that each thread will try to ﬁnd the number m within its given range. Each thread will...

code-challenge c++ functional-programming basic multi-threading

feersum

12:46 PM

How do I print a bytestring in Python 3 without getting a silly "b" and quote marks around it?

Adám

56

Q: Suppress/ print without b' prefix for bytes in Python 3

Just posting this so I can search for it later, as it always seems to stump me: $ python3.2 Python 3.2 (r32:88445, Oct 20 2012, 14:09:50) [GCC 4.5.2] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import curses >>> print(curses.version) b'2.2' >>> print(str...

python string python-3.x

feersum

I should not have to wastefully convert to a string. Plus the answer is wrong for bytes >= 0x80.

Erik the Outgolfer

@feersum I don't know if that's really possible with any one built-in, as a bytes object is not a string at all, it's really an array of integers in a string-like format

feersum

Which happens to be exactly what files are made of.

Erik the Outgolfer

1:06 PM

@feersum um, not exactly, open(file).read() returns a str

that is, unless you read the file as bytes

if you have 'rb' but you want a Unicoed str instead, just remove the argument

ATaco

1:27 PM

Abstract classes in C# confuse me but I like them.

Abstract classes no-longer confuse me.

quartata

@feersum sys.stdout.buffer.write

Or you could just do os.write(1, <bytes>) heh

feersum

1:53 PM

Do any email services have a feature like forwarding a notification that you have an email (like with the subject/sender) without forwarding the actual contents?

Erik the Outgolfer

huh

Pavel

2:24 PM

@ATaco Are they different from Java's in any way? iirc no.

ATaco

I never looked into Java's

Pavel

Ah

ATaco

2:53 PM

Progress on Funky2.0 is going well.

Swapped the token language for an OOP tokenizer, which is working much nicer.

Zacharý

3:05 PM

RAD's rewrite uses a hacky regex tokenizer ... I had to memoize a parameterless function in order to have the speed be even bearable.

Pavel

3:22 PM

@Zacharý If you memoize a parameterless function isn't that just a constant value

Zacharý

@Pavel Yeah, but I don't want a massive regex constant in my code, nor do I want main to handle that either. That was my solution to the problem.

Pavel

Maybe you could stick the regex in a seperate data file, then load that?

dzaima

@Pavel really Zacharý shouldn't even be using regex there (it's 55kb for checking if x is a number in any base iirc)

also the tokenizer's O(n²) so it's obviously gonna be horribly slow

Zacharý

3:39 PM

@dzaima Yeah, I took the naive approach, that hopefully will be fixed later.

New Meta Posts

0

Q: Explaining a challenge only with test cases and examples

I have a slightly problem. I want to post a challenge (to the sandbox) about building a matrix with X pattern. The problem is that I don't know how to explain it using technical words or mathematical expressions. If I post what is needed to do in the challenge and provide multiple input -> out...

discussion

quartata

3:57 PM

OK so like a year later I think I know why my Ruby install never worked

Pavel

Oh?

quartata

I was building something with OpenSSL and noticed that I only have static libraries for ssl and crypto

Not sure how it ended up like that

oh cool, and it was made with the nasty messed up OS X version of ar

Pavel

My ar came with Perl and I'm not sure why

quartata

4:33 PM

@WW your new avi has some very unfortunate implications

W W

hM?

Erik the Outgolfer

I think he's referring to that tongue...

W W

hm .?

quartata

think about it

Zacharý

Well, at least it's not as disturbing as the last two.

Pavel

4:37 PM

@quartata I don't get it either

quartata

@Pavel maybe when you,re older

Pavel

oh

._.

quartata

4:50 PM

This version of OpenSSL is 32 bit!!

To top it all...

Beta Decay

6:04 PM

Can anyone here write Android apps? It'd be great to have an app which simply pushed a notification to your phone every time a new message appears in your stackexchange inbox. Then, when you click on the notification it opens the link in the browser

New Sandboxed Posts

0

A: Sandbox for Proposed Challenges

I don't know how to name this challenge Given 2 inputs C = columns and rows, S = starting point draw a matrix as follow: Input 3, 2 1 2 0 2 2 0 0 0 0 Explanation I don't know how to explain this, I will need your help for this, Instead I'll show the steps of how to do it (the lo...

Beta Decay

The current SE app is crud

DJMcMayhem

I use the SE app for notifications and the mobile site for reading them

Beta Decay

Hm I suppose I could start doing that

DJMcMayhem

Although for some reason the app stopped notifying me and I don't know how to fix it

Erik the Outgolfer

6:14 PM

do you have notifications enabled for it? ;-)

DJMcMayhem

Yes

Also, I haven't used the app in ages. I forgot how terrible it really is. Especially for moderation-related actions

Erik the Outgolfer

um, maybe that's the reason then?

like, Clean Master or similar detecting you haven't used the app in ages and then you selecting it for a data cleanup

DJMcMayhem

I doubt it since I'm still logged in and my settings are still there

Erik the Outgolfer

then how did it "stop notifying" you?

DJMcMayhem

I have no idea. But it did

JungHwan Min

6:25 PM

Plus it crashes when you try to read the sandbox :/

Erik the Outgolfer

for me it just fails to load it

(Xiaomi Redmi 5 Plus 64GB 4GB Global Edition)

@DJMcMayhem ah, Quiet Hours?

JungHwan Min

Oh, wow, it fails to load now huh

It used to crash

DJMcMayhem

@EriktheOutgolfer off

Erik the Outgolfer

like, the SE app's Quiet Hours, not your phone's, right?

hm, do you allow notifications?

but you said you checked the settings

DJMcMayhem

Both are off. I allow notifications. That app has notifications enabled (in both the app's settings and mine)

Erik the Outgolfer

6:31 PM

then I'm out, maybe try clearing data or reinstalling

dunno what DJ does with the data :P

Dennis

@DJMcMayhem Same here.

DJMcMayhem

Interesting. When did you first notice it stopped?

Dennis

Now that you mentioned it. :P

I think it has been going on for a while though.

Erik the Outgolfer

@DJMcMayhem um, what is your model? not that I can help with it :P

DJMcMayhem

Google pixel (1)

Erik the Outgolfer

6:48 PM

wait isn't that too old

DJMcMayhem

Too old? It's not that old

Erik the Outgolfer

well, over a year :P

Dennis

I have a OnePlus 6, so it's not the age.

Doorknob

Notifications still work on my OnePlus 3T. (as of yesterday, at least)

Erik the Outgolfer

it does notify me, although I only recently installed the app

Zacharý

7:02 PM

<sarcasm> have you tried turning it off then back on again? </sarcasm>

Mr. Xcoder

For once WW's name and picture are (somewhat, relatively) decent.

Pavel

Erm

3 hours ago, by quartata

@WW your new avi has some very unfortunate implications

quartata

lmao

3

Mr. Xcoder

@Pavel Yeah hence the (somewhat, relatively). Much less disturbing than the last 2

DJMcMayhem

@Zacharý I will forever read that phrase in an Irish accent

Zacharý

7:09 PM

@DJMcMayhem why?

Dennis

That would sound better in "Irish".

DJMcMayhem

IT Crowd - Have You Tried Turning It Off And On Again?

►

Zacharý

LOL

quartata

ive definitely soured on the IT Crowd considering recent events

Pavel

Mm?

quartata

7:17 PM

creator turned out to be Extremely Bad

although it wasn't too much of a surprise I suppose

J. Sallé

@quartata define "Extremely Bad"?

quartata

TERF aligned

Pavel

TERF?

Erik the Outgolfer

Trans-Exclusionary Radical Feminist

Pavel

._. wat

DJMcMayhem

7:25 PM

@quartata I think you should describe it again in vaguer terms

quartata

it's pretty specific actually

Zacharý

I think he actually wants you to describe it more vaguely

Erik the Outgolfer

like, more generally

AdmBorkBork

General Specific.

quartata

so it's like when you have a group of things getting treated badly, but you want to get extremely angry about how only a certain group of that group are Real and that the other people need to be kicked out in order to preserve the ideals that were enforced by the group that's treating you badly

4

is that general enough,

Pavel

7:32 PM

"things"

quartata

This is pretty cool: github.com/browsh-org/browsh

5

@Pavel you said to make it general

Pavel

Oh yeah I saw that on HN the other week

quartata

those are your words

Pavel

@quartata When did I say that

quartata

I don't know you people all look the same

DJPavelHam

3

Good enough

Just trying to be general

@Pavel It's too bad setting up the server looks like a pain

Maybe with something like xvfb

Zacharý

7:36 PM

I'm trying to find good names for internal names of atoms: since I have both the monadic-function and dyadic-function cases lumped into one function, I'm seriously considering just naming them by their hex codes.

But I know atom2B is not a good name for +

quartata

Pyth usually names them after the most-common usage, even if they're overloaded

It makes the transpiled code look a little weird...

Adám

@Zacharý Why not use the unicode names?

quartata

Yeah pretty sure all the APL glyphs already have cute names anyways

Zacharý

@Adám That's actually a good idea!

quartata

As opposed to "squiggle, squiggle with slight upward slant, squiggle with eyes on top, ..."

J. Sallé

7:42 PM

lol @ squiggle with eyes on top ⍨

ngn

@Zacharý I name all of mine with three letters add(), mul(), rsh(), etc - this way they line up nicely in the dispatch table

Adám

@ngn rsh?

quartata

The QFTASM interpreter does that too

ngn

@Adám reshape

Pavel

I think the ~ with a diaeresis is called a selfie

J. Sallé

7:42 PM

⍨: Always watching, never satisfied.

Adám

⍥

Zacharý

@Pavel Only when the derived function is called monadically, I think

quartata

"squiggle with engagement ring..."

Adám

@quartata What it that? If squiggle is ~ and engagement ring is ○…

Zacharý

ZILDE

ngn

7:44 PM

@Adám there's a precedent for that abbreviation

Pavel

⍥: Minimalist Yoshi

quartata

@Zacharý Oh it's reflex? Hahaha

Selfie is pretty good name then

Adám

@quartata Officially the symbol is called tilde diaeresis, and the operator is called commute.

Zacharý

@Adám Or maybe ⍫.

quartata

It's the equivalent of J's ~ correct?

Adám

7:45 PM

@quartata Yes. But APL's ~ is J's -.

Pavel

⍫: Iceberg ('cause it looks like an inverted pyramid and waves)

Adám

@Pavel But icebergs float the other way.

Pavel

Do they?

Zacharý

Upside down iceberg.

ngn

global warming iceberg

Adám

7:47 PM

@Zacharý bergice.

quartata

oh snap

Adám

CMQ: What's your favourite APL character?

J. Sallé

@Adám ⍨ naturally

Zacharý

Does it have to be used in Dyalog?

Adám

@Zacharý I'll say no. What do you have in mind?

@J.Sallé Yeah, me too. I use it so much (in code, that is) that my colleagues notice.

Zacharý

7:50 PM

@Adám ⌾

Pavel

@Adám You mentioned once that you dislike using parens, does that have to do with it?

Zacharý

Or maybe because it's used a crap-ton in golfing

@Pavel Now I want to know his reaction to lisp.

quartata

Think I like ⌹ best

J. Sallé

@Pavel I'd assume so

Adám

@Pavel Yes. That, and I like trains too, where FunctionA-FunctionB-Array isn't allowed, so you have to do Array FunctionB⍨ FunctionA.

Zacharý

7:52 PM

@Adám insert obligatory reference ("I like trains")

Adám

@quartata It certainly provides solutions :-)

Pavel

What's ⌹?

J. Sallé

@Zacharý the correct answer to that is "Who doesn't?"

quartata

@Adam ba dum tsss

Zacharý

Solves a system of linear equations when used dyadically, and matrix inverse monadically

Adám

7:53 PM

@Pavel Monadic is matrix inversion. Dyadic ^ (back-ninja'd)

@Zacharý My appreciation for Lisp's syntax is contained in the following parenthesis: ().

mınxomaτ

PHP bashes PHP

5

(curated by Doorknob)

Zacharý

@Adám The one good thing about lisp is its unbeatable consistency in syntax, and that's about it.

quartata

oh dear one of the replies reminded me that ColdFusion exists

do people still use it

Zacharý

._.

@quartata wut?

ngn

@Zacharý reminds me of this

Adám

7:58 PM

@mınxomaτ Ugh.

@ngn Blocked in the UK.

Zacharý

@Adám ...

mınxomaτ

There are two PHP RFC for uniqueid. One of them wants to get rid of it, the other proposes to 'improve the uniqueness' ...

Erik the Outgolfer

@Adám use a Greek proxy, it's not blocked here

Zacharý

I'm only going to use part of the unicode name: APLFunctionalSymbolZilde is way too long

ngn

@Adám facepalm Probably due to stupid tv licensing... it's "Are you being served?" - an old British sitcom. In this scene an elderly employee says he doesn't want to be a senior clothes salesman, he just wants to work as a junior in the toys department and play with trains.

Adám

8:04 PM

@Zacharý Sure, I meant the unique part. All the special APL symbols begin with APL Functional Symbol

@ngn Yeah, it says that it is BBC that has blocked it in the UK only.

Zacharý

Yeah, I could kinda guess that, since I won't be distinguishing ⍺ and <insert-greek-symbol-here>

Erik the Outgolfer

@Adám They don't even know about DMCA complaints...psst.

Zacharý

Well: greek letters can be used as identifiers in D. I'm wondering if I should actually abuse that ... nah.

Adám

@Zacharý It would only give you ⍺∊⍳⍴⍵ anyway, and then what would you do with ⍷⍸?

AdmBorkBork

@ngn I love Are You Being Served?

Zacharý

8:15 PM

@Adám ∊ is not ε. ∊ is not in the APL section of unicode. Also, if you look at the first 32 symbols of the code page (excluding ⋄/\n), you'd understand why I'm considering that.

αβγδεζηθικ⋄λμξπρστφχψωΓΔΘΛΞΠΣΦΨΩ

Adám

@Zacharý Will you be using ε instead of or in addition to ∊?

Riker

@quartata i like your tnb posts better than your twitter

Zacharý

@Adám In addition to ∊, ⍺ε⍵ is probably going to be ⍺∊⍳⍴⍵

Adám

@Zacharý Will ∊ and ϵ be the same?

@Zacharý Why that particular definition?

Zacharý

@Adám Yes, aliases exist, the only ones that exist right now are APL -> Greek, Newline -> ⋄, and a #xx hex escape alias. But more will be added, I remember being frustrated with ∊ and ⋄ differences between GNU and Dyalog a while back.

Adám

8:19 PM

@Zacharý Maybe you should add all the aliases listed by NARS?

Zacharý

@Adám Whether indexing will give an εrror, and it looks like ∊

Adám

@Zacharý But are you not doing wrap-around indexing?

quartata

@Riker is there a difference

only difference is on twitter i can Swear more..

Zacharý

And here, you capitalize random words

quartata

i do that there too

Zacharý

8:21 PM

@Adám Well, not error, but whether a loop starts.

quartata

not random

Zacharý

Yet not even the right ones.

quartata

its about how you hear it

that seems to matter a lot to you. hearing. I dont understand it myself

Zacharý

._.

quartata

its very complicated

Zacharý

8:23 PM

._.

Pavel

There's a lot more quote marks on twitter

AdmBorkBork

@Zacharý Relevant SU link

quartata

@Pavel my phone is very old. it doesn't have smart quotes. only dumb quotes on my dumbphone

Adám

@Zacharý APL Characters and Their aliases

@Zacharý Wait, GNU uses a different ∊?

Zacharý

@quartata "dumb"? Those are the good quotes!

AdmBorkBork

8:29 PM

When you really think about it, it's amazing that we can hear at all.

quartata

hearing is rough. everything echoes. too loud to be useful.

AdmBorkBork

Have you tried turning it off and back on again?

Zacharý

Oh god not ⩽. I for some reason cannot stand that symbol

quartata

@AdmBorkBork more difficult than it sounds...

@Zacharý this is just a box for me

Pavel

@quartata Less than or equal, but the lower line is slanted instead of horizontal

Zacharý

8:32 PM

My problem with it: IT'S NO DIFFERENT THAN ≤!

quartata

oh yeah your just want to reach through the screen and adjust it, so its not crooked

evil

Zacharý

Wait ... wtf is "⍷" an APL symbol (epsilon underbar) but "∊" isn't?

Pavel

quartata owning the starboard today

quartata

its a old feeling...

Zacharý

*its, *an

quartata

8:37 PM

no.

Zacharý

yes

quartata

only when it sounds like a vowel. and who knows what it sounds like.

ive studied this language extensively, its never that simple

Pavel

how do you pronounce old then

quartata

I don't know

I can't even hear myself think it

Zacharý

*Only *vowel, *I've, *; *it's *simple. *How *then? *know. *it.

quartata

8:39 PM

listen, youre going to have a bad time if you try to be an English major on my feed here

ngn

@Zacharý There are two "element of" characters in unicode - U+2208 ("element of") and U+220A ("small element of"). For historical reasons Dyalog uses the small one.

Zacharý

@ngn Yet ⍷ got into the APL section...

I know the deal that there's two ∊'s, but they're both math operators.

Erik the Outgolfer

uh, ⍷ is used in Dyalog

Zacharý

@quartata I would never be an English major; there's too much composition, literature, and fiction.

@EriktheOutgolfer I'm talking about the APL section of the Miscellaneous and Technical block.

Adám

@Zacharý Well, it is less than or slanted equal. I wonder what slanted equality is…

ngn

8:44 PM

@Zacharý well, some APL chars happen to be generally used maths symbols

so you find them in other sections

quartata

@Adám Sounds like JavaScript

3

Zacharý

@ngn Element-of-with-underbar

quartata

Some doubles are more equal than others

Zacharý

@quartata It's just Number in JavaScript. :P

Adám

@ngn Wonder if ∈ is to ∊ what ⋀ is to ∧ and ∑ is to + and ∏ is to × etc.

feersum

8:51 PM

Is the Miscellaneous and Technical block the union of miscellaneous and technical symbols or the intersection?

Erik the Outgolfer

it would be really weird if it's the intersection

feersum

I think it would be pretty great.

But in the propositional logic<->set operations equivalence AND corresponds to insersection :)

Adám

They should have named it Miscellaneous∪Technical block or Miscellaneous∩Technical block for clarity. Why should Unicode be restricted to ASCII‽

ngn

@Adám afaik, the only reason for choosing "small element of" was that it looked better in some default font at the time they implemented it

Zacharý

@Adám It would have "n-ary"

feersum

8:55 PM

Imagine, bootstrapping Unicode in order to read the Unicode specification so you can implement Unicode.

ngn

@Adám as for ^, it's on most modern keyboards, so it's easy for a newbie to make a mistake typing it instead of ∧, so they decided to support both

Adám

@ngn Yeah, I get that one, but why does Dyalog support ∣ as | but no other homoglyphs?

Zacharý

@Adám ._.

I'll probably not be supporting the stupid homoglyphs that correspond to an ASCII character.

Adám

@Zacharý So you won't support ∧?

ngn

@Adám because it's available on most keyboard layouts

Adám

8:59 PM

@ngn What keyboard layout has ∣?