chitchcock

Stevey's Google Platforms Rant

I was at Amazon for about six and a half years, and now I've been at Google for that long. One thing that struck me immediately about the two companies -- an impression that has been reinforced almost daily -- is that Amazon does everything wrong, and Google does everything right. Sure, it's a sweeping generalization, but a surprisingly accurate one. It's pretty crazy. There are probably a hundred or even two hundred different ways you can compare the two companies, and Google is superior in all but three of them, if I recall correctly. I actually did a spreadsheet at one point but Legal wouldn't let me show it to anyone, even though recruiting loved it.

I mean, just to give you a very brief taste: Amazon's recruiting process is fundamentally flawed by having teams hire for themselves, so their hiring bar is incredibly inconsistent across teams, despite various efforts they've made to level it out. And their operations are a mess; they don't real

jboner

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

chiragchamoli

1NF is the most basic of normal forms - each cell in a table must contain only one piece of information, and there can be no duplicate rows.

2NF and 3NF are all about being dependent on the primary key. Recall that a primary key can be made up of multiple columns. As Chris said in his response:

The data depends on the key [1NF], the whole key [2NF] and nothing but the key [3NF] (so help me [Codd][1]).

2NF

Say you have a table containing courses that are taken in a certain semester, and you have the following data:

rxaviers

People

:bowtie:	😄 :smile:	😆 :laughing:
😊 :blush:	😃 :smiley:	☺️ :relaxed:
😏 :smirk:	😍 :heart_eyes:	😘 :kissing_heart:
😚 :kissing_closed_eyes:	😳 :flushed:	😌 :relieved:
😆 :satisfied:	😁 :grin:	😉 :wink:
😜 :stuck_out_tongue_winking_eye:	😝 :stuck_out_tongue_closed_eyes:	😀 :grinning:
😗 :kissing:	😙 :kissing_smiling_eyes:	😛 :stuck_out_tongue:

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

patshaughnessy

This note explains how to build Postgres from source and setup to debug it using LLDB on a Mac. I used this technique to research this article:
http://patshaughnessy.net/2014/10/13/following-a-select-statement-through-postgres-internals

1. Shut down existing postgres if necessary - you don’t want to mess up your existing DB or work :)

$ ps aux | grep postgres
pat               456   0.0  0.0  2503812    828   ??  Ss   Sun10AM   0:11.59 postgres: stats collector process       
pat               455   0.0  0.0  2649692   2536   ??  Ss   Sun10AM   0:05.00 postgres: autovacuum launcher process       
pat               454   0.0  0.0  2640476    304   ??  Ss   Sun10AM   0:00.74 postgres: wal writer process       
pat               453   0.0  0.0  2640476    336   ??  Ss   Sun10AM   0:00.76 postgres: writer process       

ueokande

Benchmark commands

Producer

Setup

bin/kafka-topics.sh \
  --zookeeper zookeeper.example.com:2181 \
  --create \

natlownes

bazel query cheatsheet

which packages depend on qtdb lib?

bazel query 'rdeps(..., //vistar/geo/qtdb:go_default_library)' --output package 

which packages does qtdb depend on?

egeromin

Asynchronous Programming and Microservices: Comparing Javascript, Erlang and Python with RabbitMQ + Celery

This article is about building asynchronous microservices. I'll compare how this can be achieved in Javascript and Erlang natively, and in Python using RabbitMQ and Celery.

But why?

My first encounter with asynchronous programming in python was when building a web backend. Upon completing a purchase, the user should eventually receive a PDF invoice by email. This didn't have to happen immediately during the request; in fact, it was better if it didn't, so as not to slow down the purchase needlessly. At the time I wasn't sure how to implement an asynchronous workflow in python, but a quick google search quickly lead me to Celery and RabbitMQ. Celery is very easy to use; the only pain is setting up a message broker -- RabbitMQ, in my case. Once you're set up, running a task in the background is as easy as writing, in myapp.py,

Maecenas

Raymond Hettinger's professional at doing code review and architecture review

P vs. NP. Pythonic vs. Non-Pythonic.

How to make use of PEP 8

1. Golden rule of PEP-8: PEP-8 onto yourself. PEP 8 is style guide, not a law book.
2. Care about intelligibility, not simply visually better
3. Transforming (Java) API to pythonic ones

Why not PEP 8