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

rgreenjr

-- show running queries (pre 9.2)
SELECT procpid, age(clock_timestamp(), query_start), usename, current_query 
FROM pg_stat_activity 
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%' 
ORDER BY query_start desc;

-- show running queries (9.2)
SELECT pid, age(clock_timestamp(), query_start), usename, query 
FROM pg_stat_activity 
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%' 

ckimrie

<?php

/**
 * 3-letter IATA City Code to CityName conversion
 *
 * Usage:
 *
 *         $city_name = City::code("LON");
 *         // "London"
 *

scaryguy

-- Firstly, remove PRIMARY KEY attribute of former PRIMARY KEY
ALTER TABLE <table_name> DROP CONSTRAINT <table_name>_pkey;

-- Then change column name of  your PRIMARY KEY and PRIMARY KEY candidates properly.
ALTER TABLE <table_name> RENAME COLUMN <primary_key_candidate> TO id;

kevin-smets

Default

Powerlevel10k

learncodeacademy

(wherever it says url.com, use your server's domain or IP)

Login to new server as root, then add a deploy user

sudo useradd --create-home -s /bin/bash deploy
sudo adduser deploy sudo
sudo passwd deploy

And Update the new password

magnetikonline

Install OSX Parallels version 10/11/12/13 tools on Ubuntu server guest

Have tested these instructions successfully under Ubuntu 16.04LTS and 14.04LTS.

• Create Ubuntu server instance under Parallels (obviously).
• Start VM, goto Actions - Install Parallels Tools... to mount the ISO image.
  • Note: if this fails, or updating tools for an existing guest you can do the following:
  • Goto Devices > CD/DVD 1 > Connect Image....
  • Select the following ISO image: /Applications/Parallels Desktop/Contents/Resources/Tools/prl-tools-lin.iso.
  • This will mount the tools CD image.

vsouza

# Set variables in .bashrc file

# don't forget to change your path correctly!

export GOPATH=$HOME/golang
export GOROOT=/usr/local/opt/go/libexec
export PATH=$PATH:$GOPATH/bin
export PATH=$PATH:$GOROOT/bin

swayson

1. Ditch Excel (for real)

    in2csv file1.xls > file1.csv

2. Conquer fixed-width formats

    in2csv -f fixed -s schema.csv data.fixed > data.csv

3. Find cells matching a regular expression

csvgrep -c phone_number -r "\d{3}-123-\d{4}" data.csv > matching.csv

AndreyStekov

SELECT pg_size_pretty(sum(pg_relation_size(quote_ident(schemaname) || '.' || quote_ident(tablename)))::bigint) FROM pg_tables 
WHERE schemaname = 'yourschema'