Sunday, March 24, 2019

TWID March 24, 2019: Gout, Music Biz, Space 2.0, Luke Starkiller, space angels, DevOps Notes

This is a post detailing some stuff I did, learned, posted and tweeted this week, I call this TWID (This week in Denis). I am doing this mostly for myself... a kind of an online journal so that I can look back on this later on. Will use the label TWID for these


Didn't do a TWID post for a couple of weeks, will continue regularly from this week on. Had an issue with my foot... still not sure if I sprained my toe or if it was gout. Didn't run for 3 weeks but started to run again this week. It feels good to run again in nature. This morning I heard so many woodpeckers


This Week I Learned

Finished the book Space 2.0: How Private Spaceflight, a Resurgent NASA, and International Partners are Creating a New Space Age
Some interesting stuff, I like how the cost went down a lot after SpaceX, Blue Horizon and others made the government contractor

Started on  the book Loonshots: How to Nurture the Crazy Ideas That Win Wars, Cure Diseases, and Transform Industries

Listened to the Tim Ferriss podcast with Safi Bahcall and in that podcast Safi mentioned that the 1st draft of Star Wars was so bad, no studio wanted it
It had these characters: Luke and Windy Starkiller.  Lol can you imagine those names having made it into the movie

Summary of the Original Script of “The Star Wars”: https://www.starwarz.com/starkiller/summary-of-the-original-script-of-the-star-wars/




Listened tot the final episode of East Coast vs West Coats Business Wars

Learned some stuff about how it is changing how artists get paid in the music industry. Artists used to be paid by album, now they are paid by the song, 1500 streams is about $9, this is cut between label/produces/songwriter. Since artists are paid by song.. , songs are getting shorter and an album will have more songs. So if you listen through an album, you are listening to more songs.  Artist are also putting the chorus at the start of the song to hook you in, because if you skip before 30 seconds or so, the play doesn't count.



Gompertz function
The Gompertz curve or Gompertz function, is a type of mathematical model for a time series and is named after Benjamin Gompertz (1779-1865). It is a sigmoid function which describes growth as being slowest at the start and end of a given time period

One example: Mobile phone uptake, where costs were initially high (so uptake was slow), followed by a period of rapid growth, followed by a slowing of uptake as saturation was reached.


The Fertility Doctor’s Secret
Her husband had given her a DNA test for Christmas because she was interested in genealogy. Her heritage turned out to be exactly what she had thought—Scottish, with English, Irish, and Scandinavian mixed in—and she never bothered to click on the link that would show whether anyone on the site shared her DNA.

Apparently she did have relatives on Ancestry.com—and not just distant cousins. The people now sending her messages said they were Cline’s secret biological children. They said their parents had also been treated by Cline. They said that decades ago, without ever telling his patients, Cline had used his own sperm to impregnate women who came to him for artificial insemination.

According to her DNA, Woock, too, was one of his children.

This so messed up, and with more and more people doing DNA testing, I think this will only increase. 

But there is a person who has 600 offspring, his name is Bertold_Wiesner


Space Angels

Space Angels is Venture Capital firm, they invest in SpaceX as well as the ones in the list below and more

Accion Systems
Accion Systems is developing revolutionary ion beam propulsion technologies for satellites, that are light, powerful, and affordable.


Analytical Space
Analytical Space is developing a cost-effective, high-throughput satellite data relay service using Cubesats with laser downlink capabilities.

Astrobotic Technology
Astrobotic will be the first private company to regularly deliver customer payloads and communication services to the Moon's surface.


Atlas Space Operations
ATLAS' network of RF satellite ground stations will offer reliable delivery of big data from LEO satellites at one-third of the cost of legacy providers.


Because Learning
Because Learning is an interactive STEM platform that enables any school to run experiments from Earth to space, through the Spire satellite network.


Bridgesat
BridgeSat is developing an optical communications network that offers secure delivery of big data from LEO at low cost and high speeds.

NanoRacks
NanoRacks is the leading commercial provider of hardware and services in low-Earth orbit for microgravity research and space station utilization.


Took some DevOps trainging this week... wanted to save the notes I took.. so I put them at the end of this post :-)

This Week I Tweeted

The lawyers who took on Big Tobacco are aiming at Realtors and their 6% fee 

Homeowners who are ready to sell their properties usually hire a real-estate agent to represent them by staging the home, photographing it, adding it to the MLS, marketing it, and showing it to prospective buyers. Sellers agree to pay that person a commission on the selling price of the home. That commission has traditionally been known as the “6%,” but it’s a little more complicated than that.

Sellers can really only negotiate with the agent they’ve hired, while agents representing buyers are generally assured of a standard 3% commission. That means that a seller’s agent who’s willing to negotiate, or one that works for a discount brokerage like Redfin RDFN, +2.93%  , will be paid less than a buyer’s agent.

Buyers can choose to be represented by an agent, or to go without one – but in any case, all commission money for both sides of the deal is always paid by the seller, thanks to a 1996 NAR rule known as the “Buyer Broker Commission Rule.”

I always thought it was strange that listing a 100K house and a 2 Million house would give you so much more money for essentially the same amount of work. Of course selling a million dollar home takes more time. Then there are people who will talk to an agent...do the house tours and not put a bid down with that agent.  If this prevails.. I wonder if the million dollar listing tv show will still be around?


Facebook Stored Hundreds of Millions of User Passwords in Plain Text for Years

Hundreds of millions of Facebook users had their account passwords stored in plain text and searchable by thousands of Facebook employees — in some cases going back to 2012, KrebsOnSecurity has learned. Facebook says an ongoing investigation has so far found no indication that employees have abused access to this data.

Facebook is probing a series of security failures in which employees built applications that logged unencrypted password data for Facebook users and stored it in plain text on internal company servers. That’s according to a senior Facebook employee who is familiar with the investigation and who spoke on condition of anonymity because they were not authorized to speak to the press.

This was maybe some logging, but still, this is bad


New Jersey becomes second state to ban cashless shops and restaurants

On Monday, New Jersey Governor Phil Murphy signed a bill banning cashless retail stores and restaurants in the Garden State. Murphy's signature makes New Jersey the second state in the US to ban cashless stores, after Massachusetts banned them in 1978.

More recently, New Jersey's move follows that of Philadelphia, which banned cashless stores earlier this month. Philadelphia's legislation was a reaction to a growing number of stores that only accept credit cards or require customers to pay with an app, like Amazon's new Amazon Go stores.

Ha, I ran into this the other day in Manhattan. Left the office with a $20 in my pocket, went to this place named Dos Torros with my co-worker, ordered a burrito and then couldn't pay, had to have my co-worker pay for me and then had to pay him back.  My main reason yo pay with cash in restaurants and smaller shops is that I don't want my credit card to be hacked, my next reason is privacy.

Also some people with bad credit might now have credit cards.. how would they pay?

I welcome this law.


Some cool stuff you might enjoy

Ten Lessons I Learned While Teaching Myself to Code

The following is a guest post by Clive Thompson (@pomeranian99), a journalist who’s written about technology and science for two decades. Clive is a longtime contributing writer for the New York Times Magazine and a columnist for Wired.

In his guest post, Clive outlines the most important lessons he learned teaching himself to code after interviewing 200+ programmers for his new book Coders: The Making of a New Tribe and the Remaking of the World.

So, you want to learn to code.

Join the club! We live in a time when, as the venture capitalist Marc Andreessen famously put it, “…software is eating the world.” So the people who know how to program are in a catalytic spot; they can make things happen. Maybe you’ve watched this from the sidelines and thought: Huh. Could I learn to do that? Perhaps you’re out of school; maybe you can’t afford either the money or the time to go back and do a four-year degree in computer science. You’ve seen a zillion of these online tutorials in coding. Could you just sort of, well, teach yourself?

The short answer is: Sure you can.

The longer answer is… the rest of this essay.

Some interesting tidbits


Some numbers that you will know by heart if you have been working with SQL Server for a while

I was troubleshooting a deadlock the other day and it got me thinking.... I know the number 1205 by heart and know it is associated to a deadlock.  What other numbers are there that you can associate to an event or object or limitation. For example 32767 will be known by a lot of people as the database id of the ResourceDb, master is 1, msdb is 4 etc etc.

A fun and quick posts with some numbers that most SQL Server peeps probably know



Some DevOps notes I took
Had some DevOps training, took some notes, didn't know where to save them, so put it here


CAMS
-------------
Culture
Automation
Measurement
Sharing


DevOps Principles 3 ways
----------------------------------------------
System Thinking  (concept to cash)  aka overall view
Amplified feedback loop  (later you find the bug.. the more it costs to fix)
Work culture to allow for learning and continues experimentation (fail fast, working code wins..sharing..)


Five Methodologies
------------------------------------
People over process over tools
Continues Delivery
Lean management (small batches, progress limits, feedback loops, visualization)
Visible Ops Change Control (repeatable build process, manage dependencies, eliminate fragile artifacts, continues improvement)
Infrastrucure as code




10 practices for DevOps success
------------------------
Incident command system
Developers on call
Status pages (transparent uptime)
Blameless postmortems
Embedded teams
The Cloud
Andon Cords (anyone can stop the release, this way something doesn't go to prod)
Dependency Injection (Inversion of Control)
Blue/Green deployment (2 system, 1 live, the other is not..deploy changes and shift traffic towards it, if problems shift back to prev version)
Chaos Monkey (trash servers occasional so that you can code for it and be prepared in case it happens out of your control.. came from Netflix)


DevOps Tools ... cart or horse?
----------------------------
Toolchain... that works together
Should be programmable.. no UI tools
Verifiable
Well behaved (from dev and operations point of view)
Write own tools if you need to....

Sunday, March 3, 2019

TWID March 3, 2019: Death by GPS, Python tool vs code, Alexa + Jenkins, Job Red Flags, Game of Thrones Fantasy League

This is a post detailing some stuff I did, learned, posted and tweeted this week, I call this TWID (This week in Denis). I am doing this mostly for myself... a kind of an online journal so that I can look back on this later on. Will use the label TWID for these

This Week I Learned

Finished the Pluralsight course Applying SQL Server 2016 Features to Real-world Data Problems by Ana Voicu

Death by GPS refers to the death of people attributable, in part, to following GPS directions or GPS maps. Death by GPS has been noted in several deaths in Death Valley, California; a lost hiker at Joshua Tree National Park in southeastern California; and incidents in Washington State, Australia, England, Italy and Brazil.

Got to the wikipedia entry after reading some comments on this link on hackernews: The Hunt for the Death Valley Germans


This Week I Tweeted

Python in Visual Studio Code – February 2019 Release

Test Explorer
This release includes the ability to visualize, navigate and run unit tests through a test explorer, a feature that is commonly requested by our users.

Validated breakpoints when debugging
This release also includes an enhancement to the debugger: validation of breakpoints targets. If a breakpoint is set on a line where breakpoints are invalid (e.g. blank lines, pass statement, lines in the middle of a multi-line statement), then it’s automatically moved to the nearest preceeding valid line

The team keeps cranking out more awesomeness every month


Jenkins + Alexa: Say Hello to Voice Controlled CI/CD 

Alexa (named after the ancient library of Alexandria) is Amazon’s Artificial Intelligence (AI) powered intelligent voice assistant that runs in the cloud. Software engineers make Alexa smarter by creating apps, called skills. From the time that I developed my first Alexa skill, I dreamed of deploying my Java projects to the cloud via voice. For me, telling Alexa to deploy my code is the ultimate level of cool! I recently made my dream a reality when I devoted a weekend to developing my newest Alexa skill, DevOps Pal. In this blog, I will show you how I developed DevOps Pal and hopefully inspire you to build your own version.


LOL, I have Alexa at home.. but I mostly use it to listen to Music. I am just wondering if they did this because they could and not because this is actually useful. Our builds build upon checkin (on dev, qa/test is scheduled), not sure why you would want to initiate it


Red Flags in Software Developer Job Descriptions

For some reason I’ve been reading a lot of job descriptions for junior devs lately and that has naturally left me with an inordinate number of opinions. I have, with great effort, condensed them here for you, dear reader.

The following aren’t pulled from any specific listings because these types of awfulness transcend the individual - and because that would be dickish. But their spirit should ring true to anyone in the trenches of the job search process.

“Technologies: Coldfusion + jQuery”
Your job search shouldn’t be driven by what’s fashionable in tech, but popularity and the market for a skill are important factors, since they influence a career track’s employability and profitability. The market for Coldfusion devs isn’t too hot (or even a thing) and jQuery simply doesn’t have the complexity or potential power of a full JS MVC. Companies advertising outdated stacks open you up to the risk of building the wrong sorts of skills, which can have far-reaching effects on your career.


One thing that caught my eye was  Coldfusion + jQuery, this is the stack that DJindexes website was built on so had to go and troll my ex co-workers  haha. One reply I got was: All of these jobs sound very interesting to me. Do they have any COBOL and JCL openings?

See also the comments on hackernews here: https://news.ycombinator.com/item?id=19268989



By now, it's not much of a secret that Motorola is working on a folding phone of its own: A patent for such a device surfaced late last year, and a subsequent report in The Wall Street Journal basically confirmed the company's plans. Despite the ensuing hype, Motorola has mostly kept quiet about its progress, but in an interview with Engadget this week, Motorola VP of Global Product Dan Dery shed some additional light on the company's ambitions.

"We started to work on foldables a long time ago," Dery said. "And we have been doing a lot of iteration."

Oh man.. now everyone is jumping on this bandwagon??  What happens when you only crack one screen? This still seems idiotic to me, especially at that price point that Samsung has.



This CTP 2.3 preview brings the following new features and capabilities to SQL Server 2019:

Big data clusters
Submit Spark jobs on SQL Server big data clusters from IntelliJ
Application deployment and management experience for deploying a variety of data-related apps including operationalizing machine learning models using R and Python, running SQL Server Integration Services (SSIS) jobs, and more
Database engine
Accelerated database recovery to provide constant time recovery and instant rollback for long running transactions
Performance enhancements in query plan recompilations, transaction log management, and Query Store
SQL Graph enhancement to enable cascaded deletion of edges upon the deletion of nodes
SQL Server Analysis Services (SSAS)
Calculation groups in tabular models that reduce the number of measures by reusing calculation logic


Installed on Sunday morning..checking out what is new and shiny. One thing that Brent Ozar noticed was the is_result_set_caching_on as a new column in sys.databases. So far I haven't heard yet how to turn it on

Some cool stuff you might enjoy

Finished The Annotated Turing: A Guided Tour Through Alan Turing's Historic Paper on Computability and the Turing Machine by Charles Petzold. a little dry at times.. but if you like math or want to learn about Turing machines, this book is for you


There is a Game Of Thrones fantasy league? 

I signed up and created a league with a bunch of co-workers
Here is how some of the scoring works


Violence:

10 Kill Random Character / White Walker / Wight (capped at 50pts)
15 Kill White Walker
25 Kill Known or Drafted Character
150 Kill Dragon
5 Incapacitate Random Character (not killed)
10 Incapacitate Known or Drafted Character (not killed)
25 Exit Bonus for Drafted Character Dying Memorably


Status/Power:

200 Take the Iron Throne
25 Sack a City / Lead a Battle Victory (must be present at victory)
25 Get a Seat on the High Council
50 Magic Use (1x Episode / Character)
50 Gain ownership of Valyrian Steel (Must keep through end of episode)
20 Have a Vision/Prophecy (1x / Episode / Character)
15 Take up a Weird/New Religion
10 Get Engaged
20 Get Married
15 Get Pregnant/Get Someone Pregnant
-20 Lose a Baby
25 Official Promotion
-25 Official Demotion
50 Come Back from the Dead
15 Act of Betrayal
15 Form / Join existing alliance
20 Ride or Control Dragon (1x / Episode)
20 MVP of Episode (Scorekeeper's Choice)
50 Revealed as Azor Ahai


I just love Times Square, here is a panorama I took'

Times Square Panorama

Monday, February 25, 2019

Cool day trip in February if you live in New Jersey.. tree tapping at Howell Living History Farm


Our family went to Howell Living History Farm for the tree tapping event 6 years or so ago, the kids were little and didn't really remember the event. We decided to repeat the event this year so that they would remember this.  From our home in Princeton it's about a 25 minute drive, not too bad

It was a cloudy day, so the pics look a little gloomy but it was not too cold

Here you can see some benches that are next to the main entrance where the shop is located

Benches

At the shop, you can see a board with all the activities and the time when the activities start. Ask someone for directions if you need to know where to go


While we were walking towards the area where they had the sap collecting buckets, these sheep came running towards us, my kids freaked out but they were very exciting to see the sheep

  Sheep Running Towards Us



A little later we saw this big duck, looked like it weighed at least 10 pounds to me, it was about the size of one of those Canada geese birds

Duck Drinking


The farm had this stack of neatly piled wood

Stack of Wood


You could actually get busy and cut the wood with this huge saw

Cut that wood


These orange roots looked really weird and much better in person

Orange roots over a stream


Here you can see the buckets that they use to collect the sap. If you stand still and don't make any noise, you can here the drops making noise when they hit the bucket. It's a pretty interesting sound

Many Buckets to tap maple sap

A close up shot of the buckets Buckets to tap maple sap

I tasted the sap as did my wife and the kids. It doesn't taste as syrup at all, it is like water with a very tiny hint of sweetness, the sap is also clear, it does not have a color


This is the evaporator, it is used to make syrup from the sap

Maple Syrup Evaporator

Open pan evaporation methods have been streamlined since colonial days, but remain basically unchanged. Sap must first be collected and boiled down to obtain pure syrup without chemical agents or preservatives. Maple syrup is made by boiling between 20 and 50 volumes of sap (depending on its concentration) over an open fire until 1 volume of syrup is obtained, usually at a temperature 4.1 °C (7.4 °F) over the boiling point of water

Boiling the sap for too long will create crystals so you have to be on top of the process and check it.  While they were doing the explaining, they also mentioned that the indigenous people would warm up stones and then drop those hot stones in the sap to create syrup.

After you are done with the presentation, you can go to the house where they will make you some old fashioned pancakes.



Farm house FarmHouse

Chickens Chickens

These chickens come inside at night because foxes and hawks will snatch them and eat them. They told us to come back in about 4 weeks because that is when they will have the little chicks.



My daughter Catherine petting this horse




After the farm, we drove to Nomad Pizza in Hopewell. If you want to eat there you will probably have to wait since they only have 10 tables or so. In the summer there is an outside area as well. This is why if we go there during the colder months we make sure to get there by 5

I had the chorizo with onion, pepper and mozzarella pizza, it was delicious



TWID Feb 25, 2019: Galaxy Fold, Huawei Mate X, Hololens 2, Juventus, Linux Fsync Issue fix for PostgreSQL, syrup

This is a post detailing some stuff I did, learned, posted and tweeted this week, I call this TWID (This week in Denis). I am doing this mostly for myself... a kind of an online journal so that I can look back on this later on. Will use the label TWID for these

This Week I Learned


Almost finished with the book The Annotated Turing: A Guided Tour Through Alan Turing's Historic Paper on Computability and the Turing Machine by Charles Petzold

It takes a lot of maple sap to create maple syrup.  The higher the sugar content of the sap, the smaller the volume of sap is needed to obtain the same amount of syrup. 57 units of sap with 1.5 percent sugar content will yield 1 unit of syrup, but only 25 units of sap with a 3.5 percent sugar content are needed to obtain one unit of syrup


Those are my youngest two trying the sap. I tried it as well, I must say there really is no taste to it.

I will make a separate post about our visit to the farm

This Week I Tweeted

Samsung’s foldable phone is the Galaxy Fold, available April 26th starting at $1,980

Samsung first teased its foldable phone back in November, and at the company’s Galaxy Unpacked event today, it’s further detailing its foldable plans. Samsung’s foldable now has a name, the Samsung Galaxy Fold, and the company is revealing more about what this unique smartphone can do. Samsung is planning to launch the Galaxy Fold on April 26th, starting at $1,980, through AT&T and T-Mobile in the US, with a free pair of Samsung’s new wireless earbuds. There will be both an LTE and 5G version of the Galaxy Fold, and Samsung is even planning on launching the device in Europe on May 3rd, starting at 2,000 euros.

Overpriced and if you damage a screen how much to repair this. I rather have a phone like the showed in the Expanse or even better a phone you can roll up so it is the size and shape of a pen. This thing is just too bulky as well. A better design would have been if there was a screen that you could slide out instead.

If you thought the Galaxy Fold was not expensive enough.. no worried The Mate X is Huawei’s 5G foldable phone... the price $2600.  Fitting name Mate X, as in mate you will need eXtra money for this one... 

Pass on both from me


Juventus share price is down 9% after their champions league result

Juventus share price is down 9% after their champions league result

  Ouch, that is not good, but Atletico played a much better 2nd half and converted their chances. Let's see if Juve can advance by scoring at least 2 at home in the return game.


Falsehoods Programmers Believe About Phone Numbers 

Some interesting things you might already know, still good to revisit this list


Some cool stuff you might enjoy

Microsoft’s HoloLens 2: a $3,500 mixed-reality headset for the factory

The Microsoft HoloLens 2 is available for preorder today for $3,500, and it’s expected to ship later this year. However, Microsoft has decided that it is only going to sell to enterprise customers who want to deploy the headset to their workers. As of right now, Microsoft isn’t even announcing a developer kit version of the HoloLens 2.

Compared to the HoloLens we first saw demonstrated four years ago, the second version is better in nearly every important way. It’s more comfortable, it has a much larger field of view, and it’s better able to detect real physical objects in the room. It features new components like the Azure Kinect sensor, an ARM processor, eye-tracking sensors, and an entirely different display system.

It has a couple of speakers, the visor flips up, and it can see what your hands are doing more accurately than before. There’s an 8-megapixel front-facing camera for video conferencing, it’s capable of full 6 degrees of tracking, and it also uses USB-C to charge. It is, in short, chock-full of new technology. But after four years, that should be no surprise.


Linux Fsync Issue for Buffered IO and Its Preliminary Fix for PostgreSQL

One of the common fixes applied to all the supported PostgreSQL versions is on – panic instead of retrying after fsync () failure. This fsync failure has been in discussion for a year or two now, so let’s take a look at the implications.

A fix to the Linux fsync issue for PostgreSQL Buffered IO in all supported versions
PostgreSQL performs two types of IO. Direct IO – though almost never – and the much more commonly performed Buffered IO.

PostgreSQL uses O_DIRECT when it is writing to WALs (Write-Ahead Logs aka Transaction Logs) only when wal_sync_method is set to : open_datasync or to  open_sync with no archiving or streaming enabled. The default  wal_sync_method may be fdatasync that does not use O_DIRECT. This means, almost all the time in your production database server, you’ll see PostgreSQL using O_SYNC / O_DSYNC while writing to WAL’s. Whereas, writing the modified/dirty buffers to datafiles from shared buffers is always through Buffered IO

Starting from kernel 4.13, we can now reliably detect such errors during fsync. So, any open file descriptor to a file includes a pointer to the address_space structure, and a new 32-bit value (errseq_t) has been added that is visible to all the processes accessing that file. With the new minor version for all supported PostgreSQL versions, a PANIC is triggered upon such error. This performs a database crash and initiates recovery from the last CHECKPOINT. There is a patch expected to be released in PostgreSQL 12 that works for newer kernel versions and modifies the way PostgreSQL handles the file descriptors. A long term solution to this issue may be Direct IO, but you might see a different approach to this in PG 12.

Some more info that I found in this hackernews comment thread that might interest you:
If you want an overview of the issue, here's a presentation from Tomas Vondra at FOSDEM 2019: https://youtu.be/1VWIGBQLtxo
Or an early recap of the "fsyncgate" issue in textual form: https://lwn.net/Articles/752063/

Related (also listed by Tomas Vondra): Linux's IO errors reporting https://youtu.be/74c19hwY2oE


As always, I will leave you with a pic I took this past week. This one is a pic of some orange roots over a stream

Orange roots over a stream

Monday, February 18, 2019

Calculating Sexy Primes, Prime Triplets and Sexy Prime Triplets in PostgreSQL


The other day I was reading something on Hackernews and someone posted a link to a Sexy Primes wikipedia article.  I looked at that and then decided to do this in SQL Server because.. why not? Then I decided to see how different this would be to do in PostgreSQL.  For the first method to create the prime numbers it's different. For the method with the CTE it is very similar


From the Sexy Primes wikipedia link: https://en.wikipedia.org/wiki/Sexy_prime


In mathematics, sexy primes are prime numbers that differ from each other by six. For example, the numbers 5 and 11 are both sexy primes, because 11 minus 5 is 6.

The term "sexy prime" is a pun stemming from the Latin word for six: sex.

If p + 2 or p + 4 (where p is the lower prime) is also prime, then the sexy prime is part of a prime triplet.

Ok I did a couple of versions of this and over the weekend.. here is what I ended up with

So first we need a table that will just have the prime numbers

I decided to populate a table with numbers from 2 till 500 and then use the sieve of Eratosthenes method to delete the non primes

This will look like this

Create this table

CREATE  TABLE  PrimeNumbers  (N INT);


In one window run this to create the function/proc

CREATE OR REPLACE FUNCTION MakePrime() RETURNS void AS $$
DECLARE I integer := 2;
BEGIN
WHILE I <= SQRT(500) LOOP
    DELETE FROM PrimeNumbers WHERE N % I = 0 AND N > I;
    I := I + 1 ; 
END LOOP;

END;

$$ LANGUAGE plpgsql;


In a another window populate the table by making the call to the function
 

INSERT  INTO PrimeNumbers(n)
SELECT N
 FROM (SELECT generate_series(2,500) as n) x;


SELECT MakePrime() ; -- Yes that is a proc call

SELECT * FROM PrimeNumbers


Thinking about it a little more I decided to do it with a CTE instead of a loop with delete statements, if your tables will be big then the delete method is probably better... it's for you to test that out :-)

What we are doing is a NOT EXISTS query against the same cte and we are filtering out numbers that are greater than the number in the current row and are not divisible by the current number


CREATE TABLE IF NOT EXISTS  PrimeNumbers  (N INT);


;WITH cte AS (
  SELECT * FROM generate_series( 2, 500 )  n
  )

INSERT INTO PrimeNumbers
SELECT n
FROM cte
WHERE NOT EXISTS (
  SELECT n FROM  cte as cte2
WHERE cte.n > cte2.n AND cte.n % cte2.n = 0)
;

SELECT * FROM PrimeNumbers;

If we run that last select statement, we should have 95 rows

2
3
5
7
 .....
 .....
463
467
479
487
491
499

Now that we have our table filled with prime numbers till 500, it's time to run the queries

Sexy prime pairs
The sexy primes (sequences OEIS: A023201 and OEIS: A046117 in OEIS) below 500 are:

(5,11), (7,13), (11,17), (13,19), (17,23), (23,29), (31,37), (37,43), (41,47), (47,53), (53,59), (61,67), (67,73), (73,79), (83,89), (97,103), (101,107), (103,109), (107,113), (131,137), (151,157), (157,163), (167,173), (173,179), (191,197), (193,199), (223,229), (227,233), (233,239), (251,257), (257,263), (263,269), (271,277), (277,283), (307,313), (311,317), (331,337), (347,353), (353,359), (367,373), (373,379), (383,389), (433,439), (443,449), (457,463), (461,467).


Here is that query for the sexy prime pairs

-- 46 rows.. sexy primes
SELECT t1.N,t2.N 
 FROM PrimeNumbers t1
join PrimeNumbers t2 on t2.N - t1.N = 6 
order by 1

It's very simple.. a self join that returns rows where the number from one table alias and the number from the other table alias differ by 6




Prime triplets
The first prime triplets below 500 (sequence A098420 in the OEIS) are

(5, 7, 11), (7, 11, 13), (11, 13, 17), (13, 17, 19), (17, 19, 23), (37, 41, 43), (41, 43, 47), (67, 71, 73), (97, 101, 103), (101, 103, 107), (103, 107, 109), (107, 109, 113), (191, 193, 197), (193, 197, 199), (223, 227, 229), (227, 229, 233), (277, 281, 283), (307, 311, 313), (311, 313, 317), (347, 349, 353), (457, 461, 463), (461, 463, 467)

A prime triplet contains a pair of twin primes (p and p + 2, or p + 4 and p + 6), a pair of cousin primes (p and p + 4, or p + 2 and p + 6), and a pair of sexy primes (p and p + 6).

So we need to check that the 1st and 3rd number have a difference of 6, we also check that that difference between number 1 and 2 is 2 or 4.  That query looks like this


-- 22 rows.. Prime Triplets
SELECT t1.N AS N1,t2.N AS N2, t3.N AS N3
 FROM PrimeNumbers t1
join PrimeNumbers t2 on t2.N > t1.N 
join PrimeNumbers t3 on t3.N - t1.N = 6
and t3.N > t2.N
and t2.n - t1.n IN (2,4)
order by 1

Here is what it looks like from pgAdmin






Sexy prime triplets
Triplets of primes (p, p + 6, p + 12) such that p + 18 is composite are called sexy prime.  p p, p+6 and p+12 are all prime, but p+18 is not

Those below 500 (sequence OEIS: A046118) are:

(7,13,19), (17,23,29), (31,37,43), (47,53,59), (67,73,79), (97,103,109), (101,107,113), (151,157,163), (167,173,179), (227,233,239), (257,263,269), (271,277,283), (347,353,359), (367,373,379)


The query looks like this.. instead of a self join, we do a triple self join, we also check that p + 18 is not a prime number in the line before the order by

-- 14 rows.. Sexy prime triplets
SELECT t1.N AS N1,t2.N AS N2, t3.N AS N3
 FROM PrimeNumbers t1
join PrimeNumbers t2 on t2.n - t1.n = 6
join PrimeNumbers t3 on t3.N - t1.N = 12
and t3.N > t2.N
AND NOT EXISTS( SELECT null FROM PrimeNumbers p WHERE p.n = t1.n +18)
order by 1



And that's it for this post.  If you are interested in the SQl Server version, you can find it here: Calculating Sexy Primes, Prime Triplets and Sexy Prime Triplets in SQL Server


More PostgreSQL posts can be found here:  /label/PostgreSQL

TWID Feb 18, 2019: Bruno Ganz, Red hat dropping MongoDB, 500px hacked, VFEmail

This is a post detailing some stuff I did, learned, posted and tweeted this week, I call this TWID (This week in Denis). I am doing this mostly for myself... a kind of an online journal so that I can look back on this later on. Will use the label TWID for these



This Week I Learned


Continued reading the book The Annotated Turing: A Guided Tour Through Alan Turing's Historic Paper on Computability and the Turing Machine by Charles Petzold

I was translating a block of T-SQL code that calculated sexy primes into PostgreSQL and found out that in order to use variables, you need to wrap it into a function in PostgreSQL . I also found out that PostgreSQL up until version 11 didn't really have stored procedures either but you could have functions behave like procs




This Week I Tweeted

Hackers wipe US servers of email provider VFEmail

"At this time, the attacker has formatted all the disks on every server," the company said yesterday. "Every VM is lost. Every file server is lost, every backup server is lost."

"This was more than a multi-password via SSH exploit, and there was no ransom. Just attack and destroy," VFEmail said.

Yep someone got pissed of for something and this was a big F U operation


500px Hacked: Personal Data Exposed for All 14.8 Million Users

The popular photo-sharing service 500px has announced that it was the victim of a hack back in 2018 and that personal data was exposed for all the roughly 14.8 million accounts that existed at the time.

In an email sent out to users and an announcement posted to its website, 500px states that it was only on February 8th, 2019, that its team learned of an unauthorized intrusion to its system that occurred on or around July 5th, 2018.

The personal data that may have been stolen by the intruder includes first and last names, usernames, email addresses, password hashes (i.e. not plaintext passwords), location (i.e. city, state, country), birth date, and gender.

Took over 6 months to find out...  that is a very long time.. as always make sure that your password is unique for each site that you use



Google will spend $13 billion on U.S. real estate in 2019, expanding into Nevada, Ohio  and Texas

CEO Sundar Pichai said in a blog post on Wednesday that the company is building new data centers and offices and expanding several key locations across the U.S., spending $13 billion this year.

Pichai outlined the plans, which include opening new data centers in Nevada, Ohio, Texas and Nebraska, the first time the company will have infrastructure locations in those states. The company is also doubling its workforce in Virginia, providing greater access to Washington, D.C., with a new office and more data center space, and expanding its New York campus at Hudson Square.

Have to spend all that that money to catch up to Amazon and Microsoft in the cloud



Red Hat Satellite to standardize on PostgreSQL backend, will be dropping MongoDB

When will MongoDB Community Edition be dropped as an embedded database within Red Hat Satellite?
This database change is a still to come, but the product team wanted to go ahead and communicate this intent to our users so they were not caught by surprise as this is a change to the underlying databases of Satellite.  No specific timing or release is being communicated at this time. At this point we’re simply hoping to raise awareness of the change that is coming to help users of Satellite prepare for the removal of MongoDB.


This is in response to the license changes that MongoDB made recently... Looking at the chart below..it looks like this is no worry to investors, MongoDB  just hit a all time high

MongoDB  just hit a all time high



RIP Bruno Ganz, who Gen X remembers as the angel in "Wings of Desire" and millennials remember as Hitler in that bunker scene.

You have seen all the parodies of course, I actually only watched this movie on January 6th 2018. Downfall is an excellent movie, if you have some time, make sure to watch it


 




Some cool stuff you might enjoy



I wrote this post for a friend so that he has a reference on how to install SonarQUbe and how to get started. This post explain how you can user SonarQube to run static code analysis against your T-SQL procs and functions



February release of @AzureDataStudio is now available! 

- Admin Pack for SQL Server extension
- Auto-sizing columns in results
- Notebook UI improvements
- Profiler Filtering
- Save Results as XML
- Deploy scripts

I am still using SSMS but maybe I will switch to DataStudio one of these days


Someone took 50,000 images of the night sky to make an 81 Megapixel image of the moon  It's beautiful 
See it here: https://www.reddit.com/r/space/comments/arer0k/i_took_nearly_50000_images_of_the_night_sky_to/ … 

mirrors of both JPG and PNG in zoomable versions here:

https://micr.io/i/clIZW  (JPG)
https://micr.io/i/WFjqr  (PNG)


Finding rows where the column starts or ends with a 'bad' character  

Another post I wrote because of a problem that a co-worker had with some data


A nice view while going to the Princeton Junction train station...  had to take a pic

Princeton Junction parking lot path

Saturday, February 9, 2019

Twid Feb 10 2019: Gemini, Stablecoin, BrightBytes, Turing, world war I restored,githistory

This is a post detailing some stuff I did, learned, posted and tweeted this week, I call this TWID (This week in Denis). I am doing this mostly for myself... a kind of an online journal so that I can look back on this later on. Will use the label TWID for these



This Week I Learned


Continued reading the book The Annotated Turing: A Guided Tour Through Alan Turing's Historic Paper on Computability and the Turing Machine by Charles Petzold

Technically this didn't happen this week, but I decided to blog about it this week: After 20+ years in IT .. I finally discovered this...

This Week I Tweeted

Microsoft buys BrightBytes DataSense to bring more data analytics to schools

BrightBytes, based in San Francisco, is an education data-analytics company and has been a Microsoft partner for years. In addition to the DataSense data-integration platform it is selling to Microsoft, BrightBytes will continue to sell its decision-support platform called Clarity which uses machine learning and predictive analytics. 

Microsoft is planning to integrate DataSense into its Microsoft Education product family. According to Microsoft, DataSense is "the leading IPaaS (integration platform as a service) solution for both education solution providers and school districts across the US."

I don't know much about this company.. but it's the data and analytics that is valuable... companies like this one are getting snapped up left and right


Winklevoss Exchange Gemini Shuts Down Accounts Over Stablecoin Redemptions

In one instance, email correspondence obtained by CoinDesk shows an OTC trader based in Latin America had his account closed after he informed Gemini that he planned to redeem several million dollars of GUSD. (A major cryptocurrency exchange, speaking on condition of anonymity, attested to the desk’s professionalism and reported that it was in good standing.)

So you can deposit money but don't you dare take it out........


Python Developers Survey 2018 Results 

Python usage as a main language is up 5 percentage points from 79% in 2017 when Python Software Foundation conducted its previous survey.

Half of all Python users also use JavaScript. The 2018 stats are very similar to the 2017 results. The only significant difference is that Bash/Shell has grown from 36% in 2017 to 45% in 2018. Go and SQL have also grown by 2 percentage points each, while many other languages such as C/C++, Java, and C# have lost their share.

In 2018 we had significantly more respondents specifying they’re involved in DevOps (an increase of 8% compared to 2017). In terms of Python users using Python as their secondary language, DevOps has overtaken web development.

The use of Python 3 continues to grow rapidly. According to the latest research in 2017, 75% were using Python 3 compared with 25% for Python 2. Use of Python 2 is declining as it’s no longer actively developed, doesn’t get new features, and its maintenance is going to be stopped in 2020.


See all the other interesting fact on the jetbrains site


Githistory
This is pretty cool.. point any public github file here and you can see the last 8  or so commits by scrolling from the top  here is what @BrentOzarULTD  sp_foreachdb changes look like ...

It looks like this

So for any file, just replace github.com in the url with githistory.xyz

For example.. the stuff in red needs to be replaced

https://github.com/BrentOzarULTD/SQL-Server-First-Responder-Kit/blob/dev/sp_foreachdb.sql
https://githistory.xyz/BrentOzarULTD/SQL-Server-First-Responder-Kit/blob/dev/sp_foreachdb.sql

Just hit this link to see it

https://githistory.xyz/BrentOzarULTD/SQL-Server-First-Responder-Kit/blob/dev/sp_foreachdb.sql

Some cool stuff you might enjoy

List of stories set in a future now past

This is a dynamic list and may never be able to satisfy particular standards for completeness. You can help by expanding it with reliably sourced entries.
This is a list of fictional stories that, when written, were set in the future, but the future they predicted is now present or past. The list excludes works that were alternate histories, which were composed after the dates they depict. The list also excludes contemporary or near-future works (e.g. set within a year or two), unless it deals with some notable futuristic event as with the 2012 phenomenon. It also excludes works where the future is passively mentioned and not really depicting anything notable about the society, as with an epilogue that just focuses on the fate of the main characters. Entries referencing the current year may be added if their month and day were not specified or have already occurred.

Some from the year 2019... Akira, Blade Runner, Dark Angel



How Peter Jackson’s team made World War I footage look new

“I thought, ‘Can we actually make this 100-year-old footage look like it was shot now?’” Jackson said on the latest episode of Recode Decode with Kara Swisher. “So it’s sharp, it’s clear, it’s stable, it looks like modern [films].”

And he had the means to do that: Over the past five years, Jackson tasked Park Road Post (a subsidiary of his production company WingNut Films) with adding color and sound to the archive footage, as well as making the frame rate consistent and similar to what we’d expect from footage shot today. The result is the new documentary “They Shall Not Grow Old,” which he said removes the “barrier between us and the actual people that were being filmed.”

This is some amazingly looking stuff... here is a video so you can see what it looks like






Build 2019 registration opens on February 27th 

Join us in Seattle for Microsoft’s premier event for developers. Come and experience the latest developer tools and technologies. Imagine new ways to create software by getting industry insights into the future of software development. Connect with your community to understand new development trends and innovative ways to code.

Wondering what new stuff they will announce


The Chemical Brothers: Setting Sun (1996)
Haven't heard Setting Sun for a while, it's an excellent running song, I have added it to my running playlist on my phone

Setting Sun is a song by The Chemical Brothers with vocals by Noel Gallagher from the group Oasis. It was released as a single in 1996 from their second album Dig Your Own Hole and reached number one on the UK Singles Chart.





 Took this on my way to the Princeton Junction train station... beautiful morning colors

  Princeton Winter Wonderland