1. NoSQL in Perspective
Jeff Smith
jeffreyksmithjr@gmail.com

2. NoSQL on Wikipedia
92 databases
8 types
6 sub-types

3. Easy Questions
Is this a graph?
Do I already have XML or JSON?
Is this a caching problem?

4. Paul Graham
on Programming Languages
Lisp
C

5. Math Problem
Lisp is just math.
Math doesn't get stale.
What in databases is just math?

6. Putting the R in RDBMSes
Relation
Attributes
Tuples

7. Database Analogy
C is to Lisp
as
Relational Algebra is to Relational Calculus
C: Lisp::Relational Algebra: Relational Calculus

8. Relational Algebra in Action
Relational Algebra:
R ⋉S = { t : t R, s S, Fun (t s) }
SQL:
SELECT * FROM audience WHERE clue > 0;

9. Relational Calculus in Action?
Relational Calculus:
{ t : {name} | ∃ s : {name, wage} ( Employee(s) ∧ s.wage = 50.000 ∧ t.name = s.name ) }
Relevant Implemented Language:
This space under construction.

10. Relational Model Utility
Essentially, all models are wrong,
but some are useful.
- George E. P. Box

11. When relations are wrong
Sparse data
Irregular data
Poorly understood interrelationships
No definable indexes
Big data
No vertically scalable hardware

12. Papers Read Around the World
Google's BigTable:
http://research.google.com/archive/
bigtable.html
Amazon's Dynamo:
http://www.allthingsdistributed.com/
2007/10/amazons_dynamo.html

13. Lessons from
Functional Programming
MapReduce:
http://research.google.com/archive/
mapreduce.html

14. MapReduce
map(String key, String value):
// key: document name
// value: document contents
for each word w in value:
EmitIntermediate(w, "1");
reduce(String key, Iterator values):
// key: a word
// values: a list of counts
int result = 0;
for each v in values:
result += ParseInt(v);
Emit(AsString(result)); [1]

15. CAP Theorem
Consistency
Availability
Partition tolerance

16. CAP Theorem?
Availability
Consistency Partition Tolerance

17. Sacrifice Availability
Consistency Partition Tolerance

18. Then, sacrifice what?
Availability Availability
Consistency Partition Tolerance

19. PACELC
In the event of a Partition,
does the system prioritize
Availability
or
Consistency
Else
does the system prioritize
Latency
or
Consistency?

20. PACELC as a Tree
Partition Else
Availability Consistency Latency Consistency

21. Traditional RDBMSes: PC/EC
Partition Else
Consistency Consistency

22. Eventually Consistent: PA/EL
Partition Else
Availability Latency

23. ELC: Replication Options
1. Update all nodes
2. Update the master node first
3. Update an arbitrary node first

24. Best of both worlds?
SQL

25. HadoopDB

26. MySQL Cluster

27. Riak Demo
N:
persisted copies
R:
read copies
W:
write copies
Strong Consistency:
R+W>N

28. Thanks
Jeff Smith
jeffreyksmithjr@gmail.com