lukeasrodgers

# Gemfile
gem 'ruby-prof'

# code to profile
require 'ruby-prof'

RubyProf.start
# run code
result = RubyProf.stop
printer = RubyProf::CallStackPrinter.new(result)

lukeasrodgers

<?xml version="1.0" encoding="UTF-8"?>
<graphml xmlns="http://graphml.graphdrawing.org/xmlns" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://graphml.graphdrawing.org/xmlns http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd">
<graph id="G" edgedefault="directed">
<node id="n0" labels=":Movie"><data key="labels">:Movie</data><data key="tagline">Welcome to the Real World</data><data key="title">The Matrix</data><data key="released">1999</data></node>
<node id="n1" labels=":Person"><data key="labels">:Person</data><data key="name">Keanu Reeves</data><data key="born">1964</data></node>
<node id="n2" labels=":Person"><data key="labels">:Person</data><data key="name">Carrie-Anne Moss</data><data key="born">1967</data></node>
<node id="n3" labels=":Person"><data key="labels">:Person</data><data key="name">Laurence Fishburne</data><data key="born">1961</data></node>
<node id="n4" labels=":Person"><data key="labels">:Person</data><data key="name">Hugo Weaving</data><data key="born">

lukeasrodgers

begin
CREATE (:`Movie`:`UNIQUE IMPORT LABEL` {`released`:1999, `tagline`:"Welcome to the Real World", `title`:"The Matrix"});
CREATE (:`Person`:`UNIQUE IMPORT LABEL` {`born`:1964, `name`:"Keanu Reeves"});
CREATE (:`Person`:`UNIQUE IMPORT LABEL` {`born`:1967, `name`:"Carrie-Anne Moss"});
CREATE (:`Person`:`UNIQUE IMPORT LABEL` {`born`:1961, `name`:"Laurence Fishburne"});
CREATE (:`Person`:`UNIQUE IMPORT LABEL` {`born`:1960, `name`:"Hugo Weaving"});
CREATE (:`Person`:`UNIQUE IMPORT LABEL` {`born`:1967, `name`:"Andy Wachowski"});
CREATE (:`Person`:`UNIQUE IMPORT LABEL` {`born`:1965, `name`:"Lana Wachowski"});
CREATE (:`Person`:`UNIQUE IMPORT LABEL` {`born`:1952, `name`:"Joel Silver"});
CREATE (:`Person`:`UNIQUE IMPORT LABEL` {`born`:1978, `name`:"Emil Eifrem"});

lukeasrodgers

# List users by average and maximum session length.
SELECT person, max(client.runtime_ms), avg(client.runtime_ms)
FROM item_occurrence
GROUP BY 1
ORDER BY 2 DESC

# List active date ranges for each deploy.
SELECT client.javascript.code_version, min(timestamp), max(timestamp)
FROM item_occurrence
GROUP BY 1

lukeasrodgers

config

• ensure config is loaded/tested in correct env

arithmetic/math

• check for divide by zero
• is integer division/rounding accounted for?
• what happens if inputs are very small/very large? or negative?
• what happens if results are negative (even though this "should never happen")
• integer overlow (in languages where matters)
• catastrohpic cancellation and other floating point concerns

lukeasrodgers

# useful if k is a very large list, and you don't want to do it all in one request
# note that consistency will not be guaranteed here (i.e. list can change during iteration)
def scan_list(k, range=1000, &block)
  i = 0
  result = []
  while l = HLR.lrange(k, i, i+range)
    break if l.size == 0
    if block_given?
      yield l
    else

lukeasrodgers

http://bonesmoses.org/2016/07/15/pg-phriday-a-postgres-persepctive-on-mongodb/
CREATE TABLE sensor_log (
  id            SERIAL NOT NULL PRIMARY KEY,
  location      VARCHAR NOT NULL,
  reading       BIGINT NOT NULL,
  reading_date  TIMESTAMP NOT NULL
);
 
\timing
 

lukeasrodgers

Keybase proof

I hereby claim:

• I am lukeasrodgers on github.
• I am lukeasrodgers (https://keybase.io/lukeasrodgers) on keybase.
• I have a public key whose fingerprint is 9E9C 2A25 69EA CF84 DF8D 6B8A 0CA0 92B0 E2F9 8F01

To claim this, I am signing this object:

lukeasrodgers

/* quickly/hackily create randomish string data with md5 */

DELIMITER $$
DROP PROCEDURE IF EXISTS user_promos;

CREATE PROCEDURE user_promos()
BEGIN
  DECLARE i INT DEFAULT 1;

  WHILE i < 5000 DO

lukeasrodgers

alert();