cpursley

PostgreSQL is Enough

• Simplify: move code into database functions
• Just Use Postgres for Everything
• Just use Postgres
• PostgreSQL is the worlds’ best database
• Postgres is eating the database world
• Hacker News discussion

Background and Cron Jobs

hartleybrody

Intro

For when you need to insert or update millions of rows and don't want to mess around with scripting to batch individual SQL commands, it's worth using postgres's built in, super-fast support for importing and exporting data from the CSV file format.

Note: that we're using the \COPY command and not the COPY command, since it allows us to work with files locally available on our machine and not worry about transferring files to the database server's file system.

Via the psql manual on \COPY:

Performs a frontend (client) copy. This is an operation that runs an SQL COPY command, but instead of the server reading or writing the specified file, psql reads or writes the file and routes the data between the server and the local file system. This means that file accessibility and privileges are those of the local user, not the server, and no SQL superuser privileges are required.

Export data from database t

warhammerkid

require 'bigdecimal'
require 'json'
require 'mqtt'
require 'prometheus_exporter'
require 'prometheus_exporter/server'

class MetricsServer
  def initialize(broker)
    @broker = broker

hartleybrody

Postgres is usually run automatically on my laptop. I also have a weekly cronjob that does brew update and brew upgrade which sometimes bumps the version of portgres that I'm running. Newer versions of the postgres server software aren't necessarily compatible with the older version's data directory structure, and so you need to "upgrade" your database to see all of your old data in the upgraded postgres server.

Trying to start the database manually with

pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

Which gives an error message and tells me where to look (note that I passed in the log directory when I ran the command)

waiting for server to start.... stopped waiting

pg_ctl: could not start server

JoshKaufman

var sendString = (function(rfb, force, sendDelay) { 
  sendDelay = sendDelay || 25;
  var _q = [];
  var _qStart = function() {
    var chr = _q.shift();
    if (chr) {
      rfb.sendKey(chr);
      setTimeout(_qStart, sendDelay);
    }
  };

magicznyleszek

Jekyll & Liquid Cheatsheet

A list of the most common functionalities in Jekyll (Liquid). You can use Jekyll with GitHub Pages, just make sure you are using the proper version.

Running

Running a local server for testing purposes:

adamlj

requests.post("https://api.mailgun.net/v2/DOMAIN/messages",
              auth=("api", "key-SECRET"),
              files={
                  "attachment[0]": ("FileName1.ext", open(FILE_PATH_1, 'rb')),
                  "attachment[1]": ("FileName2.ext", open(FILE_PATH_2, 'rb'))
              },
              data={"from": "FROM_EMAIL",
                    "to": [TO_EMAIL],
                    "subject": SUBJECT,
                    "html": HTML_CONTENT

willurd

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

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%' 

mshafrir

{
    "AL": "Alabama",
    "AK": "Alaska",
    "AS": "American Samoa",
    "AZ": "Arizona",
    "AR": "Arkansas",
    "CA": "California",
    "CO": "Colorado",
    "CT": "Connecticut",
    "DE": "Delaware",