Los Angeles R users group - Dec 14 2010 - Part 3

NoSQL

Scott Gonyea
Epoch, LLC.
@acts_as
github.com/aitrus
me@sgonyea.com

Tuesday, December 14, 2010 1

NoSQL


{ {{ {{{ NoSQL }}} }} }
* GONG *


NoSQL
So... What is it?


NoSQL
• It’s “Not SQL”
• Less Structured; Sometimes Un-Structured
• Usually Implies:
• Key-Value Store
• Document Datastore
• Graph Databases (and its Variants)
• Often not much more than that


NoSQL
Recap and Comparison


NoSQL
SELECT persons.*
FROM persons
LEFT JOIN automobiles
ON persons.id = automobiles.person_id
WHERE automobiles.color IS 'RED'

/* Wait! We can NORMALIZE this some more! */

SELECT persons.*
FROM persons
LEFT JOIN colors
AND colors.id = automobiles.color_id
WHERE colors.name IS 'RED-34'

/* Wait! ... */


NoSQL
SELECT persons.*
FROM persons
WHERE automobiles.color IS 'RED'

/* Wait! We can NORMALIZE this some more! */

SELECT persons.*, automobiles.* /* Selects */
FROM persons
LEFT JOIN automobiles /* Joins */
LEFT JOIN colors
AND colors.id = automobiles.color_id
WHERE colors.name IS 'RED-34' /* Conditions */

/* Wait! ... */


Persons
NoSQL Colors
id First Name Last Name id name
1 Seymore Butts 212 RED-34
2 Amanda Hugginkiss 213 BLUE-32

Join Table => PersonsVehicles
id vehicle_id person_id color_id
1 7384 1 212
2 7231 2 212
Automobiles
id make model Year
23192 Honda Civic 2003
19763 Chevy Tahoe 1998

Relationship: “Belongs To” => Vehicles
id identiﬁer automobile_id

Normalization 7231
7384
1FALP62W4WH128703
4WH1287031FALP62W
23192
19763


NoSQL
Key-Value Stores
AKA: Dictionary,
Hash Table, etc.

KV Database
Key Give me what’s at “John”
“John”

“Jo
hn
”
Value at “John”
“Smith”
“Smith”


NoSQL
Key-Value Stores
• Very Fast
• Simple
• Key-Value Pairs are Self-Contained
∴Easier Replication
- Twitter, Facebook, Google, etc.
- Also,Your Computer

NoSQL
Document[-Oriented] Stores
Very De-Normalized Less De-Normalized
“John Smith” “John Smith”
string ﬁrst_name John string ﬁrst_name John
string last_name Smith string last_name Smith
embedded automobiles embedded automobiles
document doc_id make Honda document doc_ref vehicle id(fd18d0af6c053886d)
string model Civic string color Red
int year 2003 string employer Epoch, LLC.
string color Red
fd18d0af6c053886d
string employer Epoch, LLC.
string make Honda
string model Civic
int year 2003
embedded features
document string breaks anti-lock
bool air_cond TRUE
geo_coord made_at 39.975542, -82.992096


NoSQL
Document[-Oriented] Stores

• Analogous to Printed Documents
• Varying Levels of De-normalization
• Documents Still Relatively Self-Contained
∴Easier Replication, Too
- Twitter, Facebook, Google, etc.


NoSQL
Graph Databases
untitled

6
4 5
1

3 2

Six Degrees of Separation
or: How you realized you have no friends :-(

NoSQL
Graph Databases
• Relationships Derived Through “Distance”
• Some Use-Cases:
• Geographic
• Networking
• Routing / Shortest Path
• Social
• Molecular Modeling
• Kevin Bacon Jokes
• Also Quite Trendy:
- Twitter, Facebook, Google [Maps, Mail, & Your Life]


NoSQL
Let’s Explore: redis


NoSQL
Let’s Explore: redis

• Versatile Key/Value Store
• Type Aware (Optional)
‣ Nums, Strings, Lists, Sets, Hashes
• Atomic Operations
• Subscriptions
• Transactional (When needed)
• Customizable Durability

redis
Needs a Better R Package

> install.packages("rredis")
> require('rredis')
> redisConnect()

> key <- 'zero'
> value <- 'hero'

> redisSet(key, value)
[1] TRUE

> redisGet(key)
[1] "hero"


redis
doRedis (rredis + foreach)
redis Subscriptions

# Uses Redis' publish/subscribe messaging to distribute workloads
require('doRedis')

registerDoRedis('jobs')

foreach(j=1:1000,.combine=sum,.multicombine=TRUE) %dopar%
4*sum((runif(1000000)^2 + runif(1000000)^2)<1)/10000000

removeQueue('jobs')


redis
Sets, From Ruby
ruby redis
require "redis"

redis = Redis.new
users = %w{albert bernard charles} redis> smembers "users"
1. "charles"
users.each {|usr|
redis.sadd "users", usr
2. "bernard"
} 3. "albert"

redis.smembers "users"
# => ["charles", "bernard", "albert"]


redis
Set Intersections, Unions, Rand
admins = %w{bernard frank alice}

admins.each do |adm|
redis.sadd "admins", adm
end

redis.sinter("users", "admins")

# => ["bernard"]

redis.sunion "admins", "users"

# => ["alice", "bernard", "albert",
"frank", "charles"]

redis.srandmember "users"

# => "albert"


redis
Atomic String Operations

redis.set "foo", "bar"
# => "OK"

redis.append "foo", "baz"
# => 6

redis.get "foo"
# => "barbaz"


redis
Atomic Operations

# Strings
redis.set "foo", "bar" # => "OK"
redis.append "foo", "baz" # => 6
redis.get "foo" # => "barbaz"

# Fixnums
redis.set "one", 1 # => "OK"
redis.incr "one" # => 2
redis.incrby "one", 3 # => 5
redis.get "empty" # => nil
redis.incr "empty" # => 1
redis.get "empty" # => "1"


Los Angeles R users group - Dec 14 2010 - Part 3

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Los Angeles R users group - Dec 14 2010 - Part 3