MongoDB presentation for SF Python's June meetup. Review of non-relational databases for the first half, focus on MongoDB for the second.

1. open-source, high-performance,
schema-free, document-oriented
database

2. RDBMS
• Great for many applications
• Shortcomings
• Scalability
• Flexibility

3. CAP Theorem
• Consistency
• Availability
• Tolerance to network Partitions
• Pick two
http://www.cs.berkeley.edu/~brewer/cs262b-2004/PODC-keynote.pdf

4. ACID vs BASE
• Atomicity
• Basically Available
• Consistency
• Soft state
• Isolation
• Eventually consistent
• Durability

5. Schema-free
• Loosening constraints - added flexibility
• Dynamically typed languages
• Migrations

6. BigTable
• Single master node
• Row / Column hybrid
• Versioned

7. BigTable
• Open-source clones:
• HBase
• Hypertable

8. Dynamo
• Simple Key/Value store
• No master node
• Write to any (many) nodes
• Read from one or more nodes (balance
speed vs. consistency)
• Read repair

9. Dynamo
• Open-source clones
• Project Voldemort
• Cassandra - data model more like
BigTable
• Dynomite

10. memcached
• Used as a caching layer
• Essentially a key/value store
• RAM only - fast
• Does away with ACID

11. Redis
• Like memcached
• Different
• Values can be strings, lists, sets
• Non-volatile

12. Tokyo Cabinet + Tyrant
• Key/value store with focus on speed
• Some more advanced queries
• Sorting, range or prefix matching
• Multiple storage engines
• Hash, B-Tree, Fixed length and Table

13. • A lot in common with MongoDB:
• Document-oriented
• Schema-free
• JSON-style documents

14. • Differences
• MVCC based
• Replication as path to scalability
• Query through predefined views
• ACID
• REST

15. • Focus on performance
• Rich dynamic queries
• Secondary indexes
• Replication / failover
• Auto-sharding
• Many platforms / languages supported

17. Good at
• The web
• Caching
• High volume / low value
• Scalability

18. Less good at
• Highly transactional
• Ad-hoc business intelligence
• Problems that require SQL

19. PyMongo
• Python driver for MongoDB
• Pure Python, with optional C extension
• Installation
• Use setuptools:
easy_install pymongo

20. Basics
• Connect:
• Insert:
• Query:

21. Document values
• None
• Special values:
• bool
• SON
• int
• Binary
• float
• ObjectId
• string / unicode
• DBRef
• dict
• datetime.datetime
• compiled re

22. • Schema-free:
• Query with selectors:

23. Advanced queries
• Sorting:
• Limit:
• Range:

24. • $gt, $lt, $gte, $lte, $ne, $all, $in, $nin
• where()
• count()
• group()

25. GridFS
• File storage in MongoDB
• File-like API for Python
• Initialize:
• Write:
• Read:

26. Other cool stuff
• Capped collections
• Upserts
• Multikeys

27. Demo

28. • Download MongoDB
http://www.mongodb.org
• Install PyMongo
• Try it out!

29. • http://www.mongodb.org
• irc.freenode.net#mongodb
• mongodb-user on google groups
• @mongodb
• mike@10gen.com