Arthur Petukhovsky petuhovskiy

No, your cryptocurrency cannot work

Whenever the topic of Bitcoin's energy usage comes up, there's always a flood of hastily-constructed comments by people claiming that their favourite cryptocurrency isn't like Bitcoin, that their favourite cryptocurrency is energy-efficient and scalable and whatnot.

They're wrong, and are quite possibly trying to scam you. Let's look at why.

What is a cryptocurrency anyway?

There are plenty of intricate and complex articles trying to convince you that cryptocurrencies are the future. They usually heavily use jargon and vague terms, make vague promises, and generally give you a sense that there must be something there, but you always come away from them more confused than you were before.

Learn Go in ~5mins

This is inspired by A half-hour to learn Rust and Zig in 30 minutes.

Basics

Your first Go program as a classical "Hello World" is pretty simple:

First we create a workspace for our project:

How To Configure PostgreSQL 12 Streaming Replication in Ubuntu 18.04

Build two boxes and install ubuntu18.04
- box1: master -> Ubuntu 18.04 with PG 12
  - static ip: 192.168.33.33
  - hostname: master
- box2: slave -> Ubuntu 18.04 with PG 12
  - static ip: 192.168.33.44
  - hostname: slave

Backup android app, data included, no root needed, with adb

Note: This gist may be outdated, thanks to all contributors in comments.

adb is the Android CLI tool with which you can interact with your android device, from your PC

You must enable developer mode (tap 7 times on the build version in parameters) and install adb on your PC.

Don't hesitate to read comments, there is useful tips, thanks guys for this !

MacOS X + oh my zsh + powerline fonts + visual studio code (vscode) terminal settings

Thank you everybody, Your comments makes it better

Install oh my zsh

http://ohmyz.sh/

sh -c "$(curl -fsSL https://raw.github.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

2021 Update: Easiest option is Justin's repo and image

Just run this from your Mac terminal and it'll drop you in a container with full permissions on the Docker VM. This also works for Docker for Windows for getting in Moby Linux VM (doesn't work for Windows Containers).

docker run -it --rm --privileged --pid=host justincormack/nsenter1

more info: https://github.com/justincormack/nsenter1

	\set aid random(1, 100000 * :scale)
	\set bid random(1, 1 * :scale)
	\set tid random(1, 10 * :scale)
	\set delta random(-5000, 5000)
	BEGIN;
	UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;
	SELECT abalance FROM pgbench_accounts WHERE aid = :aid;
	UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;
	UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;
	INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);

	[Unit]
	Description=Tunnel TCP traffic to WireGuard
	After=network.target
	Wants[email protected]

	[Service]
	Type=simple
	ExecStart=/usr/bin/udptunnel -s 443 127.0.0.1/51820
	Restart=on-failure

	# m5.2xlarge 32.0 GiB 8 vCPUs
	# s=100, n=10

	*** Only SELECTs, -T 30 -j4 -c12
	transaction type: <builtin: select only>
	scaling factor: 100
	query mode: prepared
	number of clients: 12
	number of threads: 4
	duration: 30 s

	/*
	Compiled against:

	$ gcc --version
	Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
	Apple LLVM version 8.0.0 (clang-800.0.42.1)
	Target: x86_64-apple-darwin16.7.0
	Thread model: posix
	InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
	*/