yanmhlv

CREATE USER admin; -- create user with name 'admin'
ALTER USER admin WITH PASSWORD 'hello123'; -- set password

GRANT SELECT ON users TO admin; -- give 'select' access on 'users' table to 'admin' user
REVOKE SELECT ON users FROM admin; -- revoke access on 'users' table from 'admin' user

GRANT SELECT ON ALL TABLES IN SCHEMA public TO admin; -- give access to all tables in public schema to 'admin' user
REVOKE ALL ON ALL TABLES IN SCHEMA public FROM admin; -- revoke access on all tables from 'admin' user

DROP USER admin;

yanmhlv

--- PSQL queries which also duplicated from https://github.com/anvk/AwesomePSQLList/blob/master/README.md
--- some of them taken from https://www.slideshare.net/alexeylesovsky/deep-dive-into-postgresql-statistics-54594192

-- I'm not an expert in PSQL. Just a developer who is trying to accumulate useful stat queries which could potentially explain problems in your Postgres DB.

------------
-- Basics --
------------

-- Get indexes of tables

yanmhlv

-- 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%' 

yanmhlv

TEAMCITY_PWD = /opt/teamcity

.PHONY: docker-down
docker-down:
	docker-compose down -v --remove-orphans

.PHONY: docker-up
docker-up: docker-down
	TEAMCITY_PWD=${TEAMCITY_PWD} docker-compose up -d

yanmhlv

FROM ubuntu:16.04

# Install bitcoind from PPA
RUN apt-get update
RUN apt-get install --yes software-properties-common
RUN add-apt-repository --yes ppa:bitcoin/bitcoin
RUN apt-get update

# install bitcoind (from PPA) and make
RUN apt-get install --yes bitcoind

yanmhlv

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

yanmhlv

-module(gs1).
-export([start/0, loop/1]).

% simple gen server with state

start() ->
    % io:format("Start ~p~n", [self()]),
    % spawn(fun loop/0).
    InitialState = [],
    spawn(?MODULE, loop, [InitialState]).

yanmhlv

package main

import (
	"compress/gzip"
	"io"
	"net/http"
	"strings"
)

type gzipResponseWriter struct {

yanmhlv

package main

import (
	"bytes"
	"errors"
	"html/template"
	"net/http"
	"path/filepath"
)

yanmhlv

#!/bin/bash
#####################################################
# Name: Bash CheatSheet for Mac OSX
# 
# A little overlook of the Bash basics
#
# Usage:
#
# Author: J. Le Coupanec
# Date: 2014/11/04