S. M. Shamir Imtiaz Ivanshamir

PostgreSQL is Enough

See the new site: https://postgresisenough.dev

Redis offers a great deal of support for developing efficient caching mechanisms. It takes only a couple of minutes to implement a cache mechanism and get it working with any application. Follow along to learn 25 most common Redis Interview Questions and Answers for your next senior web developer interview.

Q1: What is Redis?

Topic: Redis
Difficulty: ⭐

Redis, which stands for Remote Dictionary Server, is a fast, open-source, in-memory key-value data store for use as a database, cache, message broker, and queue.

You can run atomic operations, like appending to a string; incrementing the value in a hash; pushing an element to a list; computing set intersection, union and difference; or getting the member with highest ranking in a sorted set.

Learning Plan for Test Driven Development (TDD)

These learning resources primarily focus on Test Driven Development (TDD).

There is an emphasis on learning using PHP, Laravel and PHPUnit.
All these resources are free (at the time of writing)

Inspired by dannyfritz/commit-message-emoji

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

	Possible values for ext-name:

	bcmath
	bz2
	calendar
	ctype
	curl
	dba
	dom
	enchant

	# Redis Cheatsheet
	# All the commands you need to know


	redis-server /path/redis.conf # start redis with the related configuration file
	redis-cli # opens a redis prompt


	# Strings.

Commit type	Emoji
Initial commit	🎉 `:tada:`
Version tag	🔖 `:bookmark:`
New feature	✨ `:sparkles:`
Bugfix	🐛 `:bug:`

	/* bling.js */
	window.$ = document.querySelector.bind(document);
	window.$$ = document.querySelectorAll.bind(document);
	Node.prototype.on = window.on = function(name, fn) { this.addEventListener(name, fn); };
	NodeList.prototype.__proto__ = Array.prototype;
	NodeList.prototype.on = function(name, fn) { this.forEach((elem) => elem.on(name, fn)); };

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD