1. Persistence
Smoothie Flip
Sasser
@flipsasser
Blending
SQL
and
NoSQL

2. h6p://github.com/flipsasser/Persistence-­‐Smoothie

3. NooooooSQL

4. Photo
credit:
h6p://www.flickr.com/photos/2493/

5. Persistence

6. No ACID
Sacrifices
transacHons
and
consistency
for
performance

7. Keep what you
know
You
shouldn’t
be
running
*just*
NoSQL
at
all
Hmes

8. •Key-Value Stores
•Document Stores
•Column-based Stores
•Graph Stores

9. •Key-Value Stores
•Document Stores
•Column-based Stores
•Graph Stores

10. •Redis •Voldemort
•Tokyo Cabinet
•Riak •MemcachedDB

11. •Key-Value Stores
•Document Stores
•Column-based Stores
•Graph Stores

12. •CouchDB •Riak
•MongoDB •FleetDB

13. Map/Reduce
map = function() {
this.tags.forEach(function(tag) {
emit(tag, {count: 1});
});
}
reduce = function(key, values) {
var total = 0;
for (var i = 0; i < values.length; i++) {
total += values[i].count;
}
return {count: total};
}

14. •Key-Value Stores
•Document Stores
•Column-based Stores
•Graph Stores

15. •Cassandra
•HBase

16. •Key-Value Stores
•Document Stores
•Column-based Stores
•Graph Stores

17. •Neo4j
•HypergraphDB
•InfoGrid

18. Use Cases

19. Use Cases
Key-­‐Value
Store:
Ugly
joins
=>
denormalized
data

20. Use Cases
Document
Store:
Loose
schema,
no
ACID

21. Use Cases
Graph
Store:
Deep
relaHonships

22. Ready to jump in?

23. Too bad.
You’re
already
using
SQL.

24. Let’s mix it together

25. First Attempt
Do
it
by
hand

26. class Post
include MongoMapper::Document
key :title, String
key :body, String
key :tags, Array
key :user_id, Integer
def user
User.find_by_id(self.user_id)
end
def user=(some_user)
self.user_id = some_user.id
end
end
class User < ActiveRecord::Base
def posts(options = {})
Post.all({:conditions => {:user_id => self.id}}.merge(options))
end
end

27. Simple
I
mean,
it
“works”

28. Fat, wet models

29. Second Attempt
DataMapper
to
the
rescue

30. Photo
credit:
h6p://www.flickr.com/photos/myklrovenHne

31. DataMapper.setup(:default, "mysql://localhost")
DataMapper.setup(:mongodb, "mongo://localhost/posts")
class Post
include DataMapper::Resource
def self.default_repository_name; :mongodb; end
property :title, String
property :body, String
property :tags, Array
belongs_to :user
end
class User
include DataMapper::Resource
property :email, String
property :name, String
has n, :posts
end

32. Simpler
And
it
sHll
works

33. Ready to refactor?
I’ve
sHll
got
all
this
AcHveRecord
lying
around...

34. Go easy

35. Store App

36. •Authentication
•Products
•Purchases
•Activity stream

37. •Authentication
•Products
•Purchases
•Activity stream

38. gem install devise
Looks
like
we
can
keep
our
SQL

39. •Authentication
•Products
•Purchases
•Activity stream

40. Weight
Category
Country
of
Origin
Size Year Dimensions
Producer Label
Author
SKU Genre
Ports
ISBN Color
ASIN

41. Metadata
Don’t
need
ACID;
need
flexibility:
Document
store

42. •Authentication
•Products
•Purchases
•Activity stream

43. Transactions
Okay,
more
SQL

44. •Authentication
•Products
•Purchases
•Activity stream

45. JOIN city
Denormalize
with
a
Key-­‐Value
store

46. Okay, let’s code

48. Mix it up
Don’t
be
afraid
to
build
something
with
a
lot
of
moving
parts

49. Drawbacks

50. DataPortability.nil?
#=>
true

51. Photo
credit:
h6p://www.flickr.com/photos/francoisroche

52. gem uninstall everything
Say
goodbye
to
your
fun
AR
mixins

53. Okay, thanks
Now
I
can
relax

54. @flipsasser
Thanks
to
@mbleigh