philandstuff

russ garrett on postgres

• I like it as a default database when I don’t know what database I want to use

schemas

• I like schemas and I hate schemaless databases
• it’s useful to be able to enforce your schema before the data gets written to disk
  • rather than in your ORM!
  • CHECK constraints: ensure balance >= 0

schema changes often aren’t great

• this is why people don’t like schemas

philandstuff

Scale Summit 2014

Intro, MBS

• Chatham House Rule, so no attribution of ideas to people or companies

ideas for sessions

• bootstrapping environments (without object stores)
• service discovery
• removing spofs

philandstuff

public class User {
    public enum Gender { MALE, FEMALE };

    public static class Name {
      private String _first, _last;

      public String getFirst() { return _first; }
      public String getLast() { return _last; }

      public void setFirst(String s) { _first = s; }

philandstuff

class Need
  extend ActiveModel::Naming
  attr_reader :id
  attr_accessor :role, :goal, :benefit

  def initialize(id, exists=false)
    need = need_api_client.need(id)
    if exists
        assign_protected_attributes(need)

philandstuff

{-# LANGUAGE ExistentialQuantification #-}
import Data.Foldable
import Data.Set (Set)
import qualified Data.Set as Set
import Prelude hiding (mapM_)

data FizzBuzzTag = Fizz | Buzz deriving (Eq, Ord, Show)

type FizzBuzz = Set FizzBuzzTag

philandstuff

module FizzBuzz where
import           Data.Maybe

data FizzBuzz = Fizz | Buzz deriving Show

whenDivisible :: Integral a => a -> b -> a -> Maybe b
whenDivisible d x n = if n `rem` d == 0 then Just x else Nothing

fizzbuzz :: (Show a, Integral a) => a -> String
fizzbuzz n = if null tags then show n else concatMap show tags

philandstuff

module FizzBuzz where
import Data.Foldable (fold)
 
whenDivisible :: Integral a => a -> b -> a -> Maybe b
whenDivisible d x n = if n `rem` d == 0 then Just x else Nothing
 
fizzbuzz :: (Show a, Integral a) => a -> String
fizzbuzz n = maybe (show n) id tagStr
  where tagStr = fold [fizz n, buzz n]
        fizz = whenDivisible 3 "Fizz"

philandstuff

registers

register	fields
register	[register, fields]
field	[field, datatype]
datatype	[datatype]
address	[address, street, postcode]
postcode	[postcode, location]

philandstuff

datomic-spike

A spike into using datomic to model data registers.

Usage

You need Datomic. If you agree to the Datomic Free License you can install it using homebrew: brew install datomic.

analysis

philandstuff

2015-05-19T14:12:14.514559+00:00 app[web.1]: [error] c.j.b.ConnectionHandle - Database access problem. Killing off this connection and all remaining connections in the connection pool. SQL State = 57P01
2015-05-19T14:12:14.762639+00:00 app[web.1]: [error] application -
2015-05-19T14:12:14.762643+00:00 app[web.1]:
2015-05-19T14:12:14.762646+00:00 app[web.1]: ! @6m7idhci3 - Internal server error, for (GET) [/] ->
2015-05-19T14:12:14.762647+00:00 app[web.1]:
2015-05-19T14:12:14.762651+00:00 app[web.1]: play.api.Application$$anon$1: Execution exception[[RuntimeException: java.lang.RuntimeException: org.postgresql.util.PSQLException: FATAL: terminating connection due to administrator command]]
2015-05-19T14:12:14.762653+00:00 app[web.1]: 	at play.api.Application$class.handleError(Application.scala:296) ~[com.typesafe.play.play_2.11-2.3.8.jar:2.3.8]
2015-05-19T14:12:14.762655+00:00 app[web.1]: 	at play.api.DefaultApplication.handleError(Application.scala:402) [com.typesafe.play.play_2.11-2.3.8.jar:2.3.8]
2015-05-19