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@funny-falcon
funny-falcon / falcon.patch
Created September 14, 2012 12:07
Performance patch for ruby-1.9.3-head (applies to p194 as well)
diff --git a/array.c b/array.c
index 64647c3..618d9e3 100644
--- a/array.c
+++ b/array.c
@@ -255,15 +255,24 @@ rb_ary_modify(VALUE ary)
rb_ary_modify_check(ary);
if (ARY_SHARED_P(ary)) {
long len = RARRAY_LEN(ary);
+ VALUE shared = ARY_SHARED(ary);
if (len <= RARRAY_EMBED_LEN_MAX) {
@rgreenjr
rgreenjr / postgres_queries_and_commands.sql
Last active May 14, 2025 00:29
Useful PostgreSQL Queries and Commands
-- 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%'
@cpjolicoeur
cpjolicoeur / gist:3590737
Created September 1, 2012 23:15
Ordering a query result set by an arbitrary list in PostgreSQL

I'm hunting for the best solution on how to handle keeping large sets of DB records "sorted" in a performant manner.

Problem Description

Most of us have work on projects at some point where we have needed to have ordered lists of objects. Whether it be a to-do list sorted by priority, or a list of documents that a user can sort in whatever order they want.

A traditional approach for this on a Rails project is to use something like the acts_as_list gem, or something similar. These systems typically add some sort of "postion" or "sort order" column to each record, which is then used when querying out the records in a traditional order by position SQL query.

This approach seems to work fine for smaller datasets, but can be hard to manage on large data sets with hundreds (or thousands) of records needing to be sorted. Changing the sort position of even a single object will require updating every single record in the database that is in the same sort group. This requires potentially thousands of wri

@brandonb927
brandonb927 / osx-for-hackers.sh
Last active May 9, 2025 18:09
OSX for Hackers: Yosemite/El Capitan Edition. This script tries not to be *too* opinionated and any major changes to your system require a prompt. You've been warned.
#!/bin/sh
###
# SOME COMMANDS WILL NOT WORK ON macOS (Sierra or newer)
# For Sierra or newer, see https://github.com/mathiasbynens/dotfiles/blob/master/.macos
###
# Alot of these configs have been taken from the various places
# on the web, most from here
# https://github.com/mathiasbynens/dotfiles/blob/5b3c8418ed42d93af2e647dc9d122f25cc034871/.osx
@lexmag
lexmag / article.rb_product.rb
Created July 28, 2012 15:12
Two-way polymorphic models / Polymorphic HABTM association
class Article < ActiveRecord::Base # Product class is similar
belongs_to :user
has_many :media, as: :ownable
with_options through: :media, source: :representable do |assn|
assn.has_many :videos, source_type: 'Video'
assn.has_many :images, source_type: 'Image'
end
end
@mikhailov
mikhailov / deploy.rb
Created July 26, 2012 09:14
capistrano prettify
# standard capistrano config goes here....
# Put the maintenance screen if DB migrations take in place only
before "deploy", "deploy:delayed_job:stop"
before "deploy:migrations", "deploy:delayed_job:stop"
after "deploy:update_code", "deploy:symlink_shared", "deploy:assets_compress"
before "deploy:migrate", "deploy:web:disable", "deploy:db:backup"
after "deploy", "newrelic:notice_deployment", "deploy:cleanup", "deploy:delayed_job:restart"
@mikhailov
mikhailov / 0. nginx_setup.sh
Last active January 21, 2025 08:21
NGINX+SPDY with Unicorn. True Zero-Downtime unless migrations. Best practices.
# Nginx+Unicorn best-practices congifuration guide. Heartbleed fixed.
# We use latest stable nginx with fresh **openssl**, **zlib** and **pcre** dependencies.
# Some extra handy modules to use: --with-http_stub_status_module --with-http_gzip_static_module
#
# Deployment structure
#
# SERVER:
# /etc/init.d/nginx (1. nginx)
# /home/app/public_html/app_production/current (Capistrano directory)
#
@jboner
jboner / latency.txt
Last active May 18, 2025 17:44
Latency Numbers Every Programmer Should Know
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
@fxposter
fxposter / Gemfile
Created April 19, 2012 11:40
Test environment for rails apps
group :development, :test do
gem 'rspec-rails', '~> 2.9' # rails generate rspec:install
gem 'factory_girl_rails'
end
group :test do
gem 'spork-rails' # spork rspec --bootstrap
gem 'capybara'
gem 'launchy'
gem 'timecop'
@nherment
nherment / backup.sh
Created February 29, 2012 10:42
Backup and restore an Elastic search index (shamelessly copied from http://tech.superhappykittymeow.com/?p=296)
#!/bin/bash
# herein we backup our indexes! this script should run at like 6pm or something, after logstash
# rotates to a new ES index and theres no new data coming in to the old one. we grab metadatas,
# compress the data files, create a restore script, and push it all up to S3.
TODAY=`date +"%Y.%m.%d"`
INDEXNAME="logstash-$TODAY" # this had better match the index name in ES
INDEXDIR="/usr/local/elasticsearch/data/logstash/nodes/0/indices/"
BACKUPCMD="/usr/local/backupTools/s3cmd --config=/usr/local/backupTools/s3cfg put"
BACKUPDIR="/mnt/es-backups/"
YEARMONTH=`date +"%Y-%m"`