maierru’s gists

maierru / ets select is slow.txt

Last active August 27, 2017 11:34

ETS select is slow => O(n)

	https://github.com/sat2707/hlcupdocs/blob/master/TECHNICAL_TASK.md

	iex(9)> :ets.info(:visits)
	[read_concurrency: true, write_concurrency: false, compressed: false,
	memory: 110008228, owner: #PID<0.3544.0>, heir: :none, name: :visits,
	size: 10000740, node: :nonode@nohost, named_table: true, type: :ordered_set,
	keypos: 1, protection: :public]

	iex(11)> fun = :ets.fun2ms(fn {id, user, location, visited_at, mark} when user == 475422 -> id end)
	[{{:"$1", :"$2", :"$3", :"$4", :"$5"}, [{:==, :"$2", 475422}], [:"$1"]}]

maierru / OTP

Last active December 13, 2019 13:10

Phoenix (elixir) highload optimization

	# Move erts IO Polling to dedicated threads
	# https://github.com/erlang/otp/pull/1552

maierru / signals.go

Created January 19, 2018 15:32

go systems signals handler

maierru / accounting.sql

Created February 6, 2018 09:20 — forked from RichardKnop/accounting.sql

Basic double-entry bookkeeping system, for PostgreSQL.

	CREATE TABLE accounts(
	id serial PRIMARY KEY,
	name VARCHAR(256) NOT NULL
	);

	CREATE TABLE entries(
	id serial PRIMARY KEY,
	description VARCHAR(1024) NOT NULL,
	amount NUMERIC(20, 2) NOT NULL CHECK (amount > 0.0),
	-- Every entry is a credit to one account...

maierru / table_info.sql

Created August 6, 2018 15:39

postgresql table info sql

	SELECT l.what, l.nr AS "bytes/ct"
	, CASE WHEN is_size THEN pg_size_pretty(nr) END AS bytes_pretty
	, CASE WHEN is_size THEN nr / x.ct END AS bytes_per_row
	FROM (
	SELECT min(tableoid) AS tbl -- same as 'public.tbl'::regclass::oid
	, count(*) AS ct
	, sum(length(t::text)) AS txt_len -- length in characters
	FROM public.write_a_table_name_instead t -- provide table name once
	) x
	, LATERAL (

maierru / line_count_benchmark.rb

Created August 17, 2018 14:24 — forked from guilhermesimoes/line_count_benchmark.rb

Ruby Benchmark: Counting the number of lines of a file

	# gem install benchmark-ips

	require "benchmark/ips"

	path = "lib/rubycritic/cli/options.rb"

	Benchmark.ips do \|x\|
	x.report("read + each_line") { File.read(path).each_line.count }

	x.report("open + each_line") { File.open(path, "r").each_line.count }

maierru / gist:c6cffec05574fb2c0ed354348997fdfa

Created December 11, 2018 12:17

mac os background notification in the ssh session

sleep 10 && echo -en "\007"

maierru / freebsd.txt

Created January 14, 2019 13:23

mac os x bash last day of each month

	$ for i in {1..12}; do date -v1d -v-1d -v-${i}m +%Y-%m-%d; done
	2018-11-30
	2018-10-31
	2018-09-30
	2018-08-31
	2018-07-31
	2018-06-30
	2018-05-31
	2018-04-30
	2018-03-31

maierru / clear-sidekiq-jobs.sh

Created April 15, 2019 07:35 — forked from wbotelhos/clear-sidekiq-jobs.sh

Clear Sidekiq Jobs

	# 1. Clear retry set

	Sidekiq::RetrySet.new.clear

	# 2. Clear scheduled jobs

	Sidekiq::ScheduledSet.new.clear

	# 3. Clear 'Processed' and 'Failed' jobs

maierru / client_example

Created November 8, 2019 23:42 — forked from sandro/client_example

Ruby select socket server. An example of a single-threaded, event-driven (select) server.

maierru maierru