No SQL is not about SQL

No SQL is a Zoo.. Key-Value Stores

BigTableSimpleDB

Azure Table

Wide Column Stores

Document Stores Graph Databases

Why not Traditional RDBMs?Offer incredibly useful guarantees and have been battleworn and tested.

Referential Integrity

ACID Transactions

And SQL..

SQL is a powerful expressive DSL (Domain Specific Language) that many, many people understand.

So Why No SQL?

Web Scale

Web scale can be done in SQL

How?• Vertical Part / Logical Sharding

(Instagram)• Caching (28 terabytes Facebook,

2008)• SQL + No SQL• Think about your Architect

Want to learn more? Spend time on http://highscalability.com/

But a reasonable question is..

How much time should we be devoting to managing scaling problems versus adding business value to these systems?

So what are we giving up?

Availability

Consistency

Partitiontolerant

MongoDB

MySQLSQL Server

Oracle

RDBMsHBase (Hadoop)

Google BigTable

DynamoCouch Cassandra

Voldemort

Redis

SimpleDB

CAP

FriendsWhoCook.comA social network of friends who enjoy cooking great food.

- Add my Recipes - Add my friends- Show my friends- Like / Comment on my Friend’s Recipes- Search recipes of my friends, their

friends, and so on by.

Problem 1: Store Recipes

Fairly Simple Objectclass Recipe {

Image PhotoList<Comments> CommentsList<Ingredients> IngredientsList<ProfileId> LikesCategory RecipeCategory}

Becomes a complex RDBM’ess

Object-Relational Impedance Mismatch

No SQL: Document Store• Data element is a document• Documents grouped into collections• Often store in JSON• Works great with Domain Driven

Design• Schema-less

Document Store Examples• MongoDB (PC)• CouchDB (PA)• RavenDB (PA)

DEMO: MongoDB

Demo: CouchDB

Problem 2: Model the Social Graph

Friends in RDBMS

For a more sophisticated view of modeling graphs in an RDBMs:http://www.slideshare.net/quipo/rdbms-in-the-social-networks-age

Get my Friends

Declare @ProfileID int

SELECT FirstDegreeProfile.ID, FirstDegreeProfile.FirstName, FirstDegreeProfile.LastName

FROM Profile AS FirstDegreeProfileJOIN Friendship ON FirstDegreeProfile.ID = Friendship.FriendIDWHERE Friendship.ProfileID = @ProfileID

Friends and their friends

Declare @ProfileID int Set @ProfileID = 1

Select FirstDegreeFriendship.FriendId as MyFriendId, SecondDegreeProfile.ID as

SecondDegreeId, SecondDegreeProfile.FirstName as SecondDegreeFirstName, SecondDegreeProfile.LastName as SecondDegreeLastName

from Profile as SecondDegreeProfileJoin Friendship as SecondDegreeFriendship ON SecondDegreeProfile.ID = SecondDegreeFriendship.FriendIDjoin Friendship as FirstDegreeFriendship ON SecondDegreeFriendship.ProfileID = FirstDegreeFriendship.FriendIDWhere FirstDegreeFriendship.ProfileId = @ProfileId

/* Note: A much better solution would use a recursive CTE to compute transitive closure */

Graph Databases• Optimized for graphs data• Check out Neo4J

Problem 3: Schemaless / Big Data

Facebook's Network: Credit Traud & Frost, UNC-Chapel Hill

How do we ask these questions?• After we changed the “like” button

icon for half of our users, did we get more or less likes from that sample?

• Of users who click on our ads, what pages did they spend the most time on?

• Which hidden patterns might make us competitive that we aren’t even aware of?Want to get far ahead of the pack? Read “The Lean Startup” by Eric Ries

Is this Actionable?

How about this?

Wide Column“A Bigtable is a sparse, distributed, persistent multidimensional sorted map”

Source: http://jimbojw.com/wiki/index.php?title=Understanding_Hbase_and_BigTable

MapReduceMap(k,v) [(k1, v1), (k2, v2), (k1, v3), (k3, v4)]Map(k, v) (list of intermediate key / value pairs)

Internal Step: Takes list of intermediate key value pairs and converts to a key / list of values.

Reduce(k, [v1, v2, v3…]) (k, n1), (k, n2)

One Down Side…• We have to have smart people write

MapReduce programs and the problems need to be expressible as Map Reduce..

• General solutions are BIG money.

Final thought: Big Data is BIG

= ?

Things to Read• Bigtable: A Distributed Storage System for

Structured Data • Dynamo: Amazon’s Highly Available Key-value Store• MapReduce: Simplified Data Processing on Large

Clusters• The Google File System• Towards Robust Distributed Systems • http://jimbojw.com/wiki/index.php?

title=Understanding_Hbase_and_BigTable

Creative Commons Acknowledgments and Thanks!

Bobwitloxrosipaw