~/devreads

4 Oct 2018

3 Oct 2018

2 Oct 2018

1 Oct 2018

1 min read

Small business admin is a headache for any busy entrepreneur. But there are ways to minimise the pain, speed up processes and improve business performance.

Stanko 2 min read

This is something I keep rediscovering, because I keep forgetting it. JSON.stringify will omit all object attributes that are undefined. In most cases, it doesn't really matter, because if we parse that string back, and try to access that attribute - it will be undefined by design. Check the example below: const user = { name: 'Stanko', phone: undefined };…

28 Sept 2018

26 Sept 2018

lukaseder 1 min read

At a customer site, I recently refactored a “slow-by-slow” PL/SQL loop and turned that into an efficient set based UPDATE statement saving many lines of code and running much faster. In this blog post, I will show how that can be done. The blog post will focus on Oracle and UPDATE, but rest assured, this … Continue reading How to…

sqlbulk dmlbulk updatedata change statementdata change table

1 min read

At Jane Street, we often work with data that has a very low signal-to-noise ratio, but fortunately we also have a lot of data. Where practitioners in many fields might be accustomed to having tens or hundreds of thousands of correctly labeled examples, some of our problems are more like having a billion training examples whose labels have only a…

25 Sept 2018

24 Sept 2018

23 Sept 2018

Matthew Green 10 min read

This blog is mainly reserved for cryptography, and I try to avoid filling it with random “someone is wrong on the Internet” posts. After all, that’s what Twitter is for! But from time to time something bothers me enough that I have to make an exception. Today I wanted to write specifically about Google Chrome, … Continue reading Why I’m…

googlechromeprivacy

21 Sept 2018

lukaseder 1 min read

Everyone knows the SQL SUM() aggregate function (and many people also know its window function variant). When querying the Sakila database, we can get the daily revenue (using PostgreSQL syntax): The result will look something like this: date |daily_revenue |cumulative_revenue -----------|--------------|------------------- 2005-05-24 |29.92 |29.92 2005-05-25 |573.63 |603.55 2005-05-26 |754.26 |1357.81 2005-05-27 |685.33 |2043.14 2005-05-28 |804.04 … Continue reading How to…

sqlaggregate functionjavamultiplicationwindow function

20 Sept 2018

lukaseder 1 min read

SQL is a verbose language, and one of the most verbose features are window functions. In a stack overflow question that I’ve encountered recently, someone asked to calculate the difference between the first and the last value in a time series for any given day: Input volume tstamp --------------------------- 29011 2012-12-28 09:00:00 28701 2012-12-28 10:00:00 … Continue reading How to…

sqlfirst valuelast valuemysqlpostgresql

1 min read

Last year we held a machine learning seminar in our London office, which was an opportunity to reproduce some classical deep learning results with a nice twist: we used OCaml as a programming language rather than Python. This allowed us to train models defined in a functional way in OCaml on a GPU using TensorFlow.

19 Sept 2018

jonskeet 1 min read

This is more of a quick, explanatory “heads-up” post than anything else. On March 31st 2018, I started an experiment: I created a new Stack Overflow user called “Daisy Shipton” with no picture and a profile that just read “Love coding in C#” (or similar). I wanted to see how a new user presenting with … Continue reading Farewell, Daisy…

stack overflow

18 Sept 2018

17 Sept 2018

16 Sept 2018

Dave Cheney 1 min read

Ousterhout’s opus is tearing up tech twitter at the moment. But for those outside the North American prime shipping service area, we’re shit out of luck until a digital version is available. Until then, here’s Ousterhout’s Google Tech talk: Slides: https://platformlab.stanford.edu/Seminar%20Talks/retreat-2017/John%20Ousterhout.pdf CS190: https://web.stanford.edu/~ouster/cgi-bin/cs190-winter18/index.php

internets of interest

15 Sept 2018

14 Sept 2018

13 Sept 2018

Daniel Schmidt 3 min read

Often when you develop an application performance matters. The most important asset you have when it comes to perceived performance is the response time of your backend services. If you use GraphQL it is most likely the system that comes right before the user-facing application, so it should be the central part to take a look at when it comes…

graphqlopentracingtrace-graphqlgraphql-with-apolloperformance-tracing

11 Sept 2018

kevin 5 min read

It's Rail Safety Month and last month at the Caltrain CAC we got a presentation on suicides on the Caltrain line. I've added some key papers that study railway suicide to this Github repository. At a high level, they show: There are several factors that predict suicide incidence. There are several factors that have been […]

caltrain

10 Sept 2018

9 Sept 2018

7 Sept 2018

lukaseder 1 min read

I recently stumbled upon a curious query on a customer’s productive Oracle database: Two things caught my attention: The query was executed many billions of times per month, accounting for about 0.3% of that system’s load. That’s 0.3% for something extremely silly! I don’t think that customer would ever qualify the DUAL table as SYS.DUAL, … Continue reading Beware of…

sqlcontext switchoracleperformancepl sql

Stanko 1 min read

I want to share a hack (or a trick if you prefer) my colleague Marko showed me today. What is the problem? We want our flex items to be equally distanced between each other and from the parent's edge. Unforunately space-evenlyI wasn't aware of this property, thank you Marc for mentioning it in the comment below. is not supported in…

5 Sept 2018

4 Sept 2018

3 Sept 2018

lukaseder 1 min read

I’ve stumbled across this fun SQL question on reddit, recently. The question was looking at a time series of data points where some events happened. For each event, we have the start time and the end time timestamp start end ----------------------------------- 2018-09-03 07:00:00 1 null 2018-09-03 08:00:00 null null 2018-09-03 09:00:00 null null 2018-09-03 10:00:00 … Continue reading Find the…

sqlgapstime serieswindow functions

Dave Cheney 3 min read

This is a short response to the recently announced Go 2 generics draft proposals Update: This proposal is incomplete. It cannot replace two common use cases. The first is ensuring that several formal parameters are of the same type: contract comparable(t T) { t > t}func max(type T comparable)(a, b T) T Here a, and […]

goprogramminggenerics

2 Sept 2018

31 Aug 2018

blog.muffn.io (muffn_) 1 min read

Introduction # This post will be a brief intro into VMWare’s distributed switch technology and how to get your feet wet in the setup. This will not cover the advanced features or in-depth configuration but a followup may come in the future.

30 Aug 2018

jgamblin 1 min read

The new rest API in Burp 2.0 it is going to be amazing but it will allow things like this 9 line shell script I wrote this morning that will grab all public bounty sites from @arkadiyt’s bounty-targets-data repo and kick off a full scan. https://gist.github.com/jgamblin/c22c0791af7572280d7fd569141650fe I almost didn’t post this blog because I *think* this script is, in general,…

uncategorized

29 Aug 2018

4 min read

At SoundCloud, we follow best practices around continuous delivery, i.e. deploying small incremental changes often (many times a day). In…

28 Aug 2018

lukaseder 1 min read

One of the more frequent questions people have when switching from JPA to jOOQ is how to migrate from using JPA’s first level cache? Speaking of that, are there any jOOQ guides on how to replace JPA? Any patterns on how to work without EntityManager to manage in-memory state (EM#merge()), 1st level cache, etc. — … Continue reading A Frequent…

jooq-in-useactiverecordcrudentitiesfirst level cache

jgamblin 1 min read

I spend a lot of time working with MacOS and I have noticed that out of the box the operating system has some basic security settings that are not enabled by default so I have built a small script that automates configuring these. It does the following: Requires Password Immediately After Sleep. Turns On Firewall. Enables Stealth Mode. Disables Remote…

uncategorized

Schakko 1 min read

Just a quick reminder how to run a Spring Boot JAR (or any other self JAR executable) with SELinux enabled: chcon --type=java_exec_t /opt/myapp/spring-boot-app.jar To make this persistent you have to use the bin_exec_t type as java_exec_t is just an alias: # apply the bin_exec_t semanage fcontext -a -t bin_exec_t /opt/myapp/spring-boot-app.jar […] The post Running a Spring Boot JAR service with…

javalinux

23 Aug 2018

22 Aug 2018

Stanko 1 min read

Yesterday, one of my colleagues shared UI Movement website. It resulted in me playing with random animations trying to replicate mockups I liked. Here are the results:

21 Aug 2018

20 Aug 2018

19 Aug 2018

Dave Cheney 1 min read

This weekend I’ve been freshening up the introductory material for a workshop that Francesc Campoy and I are teaching at GopherCon this month. As part of my research, these videos have been on high rotation. The first video by Sophie Wilson, the designer of the first ARM chip from which both the company and the line […]

internets of interest

18 Aug 2018

bohops 11 min read

TL;DR There are several ways that attackers can leverage COM hijacking to influence evasive loading and hidden persistence. A few examples include CLSID (sub)key abandonment referencing, key overriding, and key linking. There are several programs and utilities that can invoke COM registry payloads including Rundll32.exe, Xwizard.exe, Verclsid.exe, Mmc.exe, and the Task Scheduler. In the traditional […]

uncategorized

16 Aug 2018

15 Aug 2018

lukaseder 1 min read

Oracle is one of the few databases that implements the SQL standard ORDBMS extensions, which essentially allow for nested collections. Other databases that have these features to some extent are CUBRID, Informix, PostgreSQL. Oracle has two types of nested collections: The main difference at first is that a nested table can be of arbitrary size, … Continue reading How to…

sqlapplyexceptintersectmultiset

14 Aug 2018

Tamas Kadlecsik 7 min read

In this post, I’m going to teach how you can debug a Node.js app in a Docker container to catch bugs that cannot be revealed in any other way. The post How to Debug a Node.js app in a Docker Container appeared first on RisingStack Engineering.

devopsedited

13 Aug 2018

11 Aug 2018

Henrik Warne 2 min read

I use a shell every day. Almost always, I want to repeat a previous command, or repeat it after a slight modification. A very convenient way is to use arrow-up to get the most recent command back. Another common trick … Continue reading →

workcommand-linehistoryshellshortcut

10 Aug 2018

1 min read

Mathematics students often hear about the classic “blue-eyed islanders” puzzle early in their career. If you haven’t seen it, read Terry Tao’s excellent writeup linked above. The solution uses induction and the idea of *common knowledge—*I know X, and you know that I know X, and I know that you know that I know X, and so on—to make a…

9 Aug 2018

8 Aug 2018

Ben Adida 10 min read

Over the last few months, we’ve been readying Clever SSO for our biggest year ever. We want students across the country logging in quickly and reliably to all of their learning applications. A couple of months ago, we described our initial stress testing approach. In this post, we want to tell you more about this […] The post Clever SSO…

resiliency

12 min read

For several years this blog was generated using the PHP static site generator Sculpin. I switched to Grav before deciding it was not for me. My blog does not contain dynamic data that requires PHP processing, and static HTML with JS is fine. One of the issues I had with Grav was its requirement of both a PHP-FPM and Nginx/Apache…

dockerlets-encryptansiblehugoblog

7 Aug 2018