miguelff

Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers

miguelff

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

miguelff

Macbook Arch Guide

• Installation
• General Setup
• System Time
• Display
• Keyboard
• Touchpad
• Sound
• Bluetooth

miguelff

select
    concat(
        'create table ',
        table_name,
        '(',
        string_agg(
                concat(
                        column_name,
                        ' ',
                        CASE when is_nullable = 'YES' THEN 'Nullable(' END,

miguelff

package main

// The aim of this example is to illustrate backpressure using golang channels and go routines.
//
// This is the basis for a simple data processing service which could either be reading from
// some internal queue or a socket of some sort.

import (
	"fmt"
	"math/rand"

miguelff

Octave CheatSheet

GNU Octave is a high-level interpreted language, primarily intended for numerical computations.
(via GNU Octave)

Basics

• not equal ~=
• logical AND &&

miguelff

WITH fulfillment_method_classification AS (
    SELECT
      f._shop_key,
      f."order id",
      f."shop shipping country",
      f."fulfillment id",
      CASE
      WHEN ofsd."is shopify shipping fulfillment" = 'Fulfilled via Shopify Shipping'
        THEN 'Shopify Shipping'
      WHEN _api_client_key = -2

miguelff

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

miguelff

# use the latest ubuntu environment (18.04) available on travis
dist: xenial

language: go

# Force-enable Go modules. Also force go to use the code in vendor/
# These will both be unnecessary when Go 1.13 lands.
env:
  - GO111MODULE=on
  - GOFLAGS='-mod vendor'

miguelff

Assuming you llvm installed (comes as standard on Mac OS Mavrick xtools)

Create a helloworld.c file:

  #include<stdio.h>
  
  int main()
  {
 int x=3;