njakobsen’s gists

njakobsen / sphinx_indexing.rb

Last active May 19, 2019 16:50

Automatic removal of stale Sphinx documents during Realtime Indexing

	# Improve indexing to remove records whose sphinx document id is stale due to changes to the number/order of indices
	module SphinxIndexing
	# Delete existing record before inserting new ones. This avoids the need to rebuild the index after adding or removing
	# an index. Without this, the old indexed record would not be deleted since Sphinx's calculation of that record's id
	# would not match now that the number/order of indices has changed.
	module Transcriber
	def copy(*instances)
	return unless instances.present?

	ids = instances.map(&:id).compact

njakobsen / gist:6395146

Last active September 29, 2016 20:00

Poor man's outer join for rails. Just extend ActiveRecord::Base with this beauty, and voila! MyModel.outer_joins(:some_association).ftw!

	module OuterJoins
	def outer_joins(*associations)
	pattern = / (?:INNER )?JOIN /i
	scope = all
	associations.each do \|association\|
	inner_join_sql = scope.unscoped.joins(association).to_sql
	outer_join_sql = inner_join_sql.gsub(pattern, ' LEFT OUTER JOIN ')
	scope = scope.joins(outer_join_sql[/LEFT OUTER JOIN .+/])
	end

njakobsen / gist:6393783

Last active December 22, 2015 01:08

Test performance of ActiveRecord Includes. This is a test script designed to test for a performance regression when using the .includes() method on a scope.

	begin
	class CreateModels < ActiveRecord::Migration
	def change
	create_table :items do \|t\|
	end

	create_table :events do \|t\|
	t.belongs_to :item
	end

njakobsen / live_database_dump.rb

Last active November 5, 2021 02:28

Live stream a database dump (or any other STDOUT) using Rails 4. Why would you want this? If you have a large database dump and want to avoid storing it in memory as Rails streams it. This allows pipe the dump directly into the http response instead of storing it as a file, sending it, and then deleting it. Let me know what you think! I've teste…

	class DatabaseController < ApplicationController
	def database_dump
	database = Rails.configuration.database_configuration[Rails.env]["database"]
	send_file_headers!(:type => 'application/octet-stream', :filename => "#{database}_#{Time.now.to_s(:human)}.backup")

	pipe = IO.popen("pg_dump '#{database}' -F c")
	stream = response.stream
	while (line = pipe.gets)
	stream.write line
	sleep 0.0001 # HACK: Prevent server instance from sleeping forever if client disconnects during download

njakobsen / association_delete_all_test.rb

Created May 12, 2012 19:20

model.association.delete_all performance issue

	require 'active_record'
	require 'logger'

	# Print out what version we're running
	puts "Active Record #{ActiveRecord::VERSION::STRING}"

	# Connect to an in-memory sqlite3 database (more on this in a moment)
	ActiveRecord::Base.establish_connection(:adapter => 'sqlite3', :database => ':memory:')

	# Create the minimal database schema necessary to reproduce the bug

njakobsen / dependent_delete_all_test.rb

Created November 18, 2011 01:46

Rails 3.1 poor handling of :dependent => :delete_all

	require 'active_record'
	require 'logger'

	# Print out what version we're running
	puts "Active Record #{ActiveRecord::VERSION::STRING}"

	# Connect to an in-memory sqlite3 database (more on this in a moment)
	ActiveRecord::Base.establish_connection(:adapter => 'sqlite3', :database => ':memory:')

	# Create the minimal database schema necessary to reproduce the bug

njakobsen / gist:162963

Created August 5, 2009 21:10

	class EntityViewSweeperWorker < Workling::Base

	# Expires the view fragments for a particular entity based on options[:type] and options[:id]
	def expire_fragment_for_all(options)
	expire_fragment(/#{options[:type].tableize}\/#{options[:id]}\/views\//)
	end
	end

Nicholas Jakobsen njakobsen