Introduction to SQLite, given at the Champaign Urbana Database Users Group (cuDBug) on 20 June 2013. http://www.meetup.com/cuDBug/

1. An Introduction to
SQLite
The Most Popular Database In theWorld
Jay Kreibich
jay@kreibi.ch
cuDBug
20 June 2013

2. My history with DBs
• Undergrad at UIUC, the Web 1.0 era
• Full time software developer for 17 years
• 8 years at CITES, including many network
monitoring and management tools
• Almost 7 years atVolition, the last three years
doing data collection and analysis

3. Relationship with DBs
• School: Databases are for COBOL
programmers
• Early work: Databases are useful
• Later work: Database theory is amazing

4. My history with SQLite
• First learned about it at WWDC 2004
• Used for a number of work projects
• Tried to stuff Wikipedia dump onto an
ebook reader

5. So I wrote a book...

6. So I wrote a book...
• Great White Heron
• No, I didn’t get to choose
•August 2010
• 2.5 years to write & edit

7. What is SQLite?
The power of a full RDBMS...
...without all the headaches.

8. What is SQLite?
• Database-in-a-file
• Self-Contained
• Serverless
• Zero-configuration
• Concurrent Access
• ACID compliant
• In the Public Domain
SQLite is an SQL based RDBMS that is...

9. Database-in-a-File
• Database instance is a common file
• File contains schema, data, blobs, etc.
• Files are cross-platform
• Endian
• Word size (32 bit & 64 bit)
• Encoding (UTF-8, UTF-16be, UTF-16le)

10. Self-Contained
• The database engine is compiled directly
into the application
• No external libraries or processes

11. Serverless
Application Client lib ServerServer
Procs
Typical Client/Server
SQLite
Application SQLite

12. Zero Configuration
• No server means no server admin, no DBA
• Application can self-configure DB

13. Concurrent Access
• SQLite uses file locking to allow safe
concurrent access from multiple
connections, threads, or processes
• Local processes only
• Network storage typically does not work

14. ACID Compliant
• SQLite provides full ACID transactions
• Two different transaction methods:
• Rollback Journal
• Write-Ahead Log
• Different levels of locking and access

15. Public Domain
• Core source code and algorithms are
in the Public Domain
• Rigorously enforced
• “SQLite” name is still under trademark
• Causes more problems than it solves

16. SQLite Types
• Signed 64-bit Integers
• IEEE 754 64-bit Float Point
• Unicode Text
• BLOBs
• NULL
• (No date/time types; no “numeric” type)

17. Other Features
• Connection can “attach” multiple DBs
• SQLite uses manifest typing
• Column types are not rigidly enforced
• Very few issues
• DDL is transactional

18. Other Features
• Supports in-memory DBs (very fast)
• Depends on file access for Auth/Auth
• Right Outer Joins not supported (Left is)
• Triggers are supported
• Custom functions/aggs, but not in-DB

19. Other Features
• Virtual Tables
Virtual DB
Engine
Query Planner
Optimizer
API
Virtual DB
Engine
Query Planner
Optimizer
API
Application
Code

20. Good Uses for SQLite
• Database Junior
• Application Cache
• Archives and Data Stores
• Client/Server Stand-in
• Application File Format
• Teaching Tool
• Generic SQL Engine (external data source)

21. Bad Uses for SQLite
• High Transaction Rates
• Very Large Datasets
• Detailed Access Control
• Client/Server or Multi-Host
• Advanced Replication

22. SQLite Distribution
• Code for SQLite library
• Code for sqlite3 CLI application

23. Most popular?
SQLite is, most likely, the
most popular database in the world
by number of database instances.
You use it all the time.

24. Most popular?
• Firefox, Safari,
Chrome
• iTunes, MacOS X
• Thunderbird, Mail
• McAfee
• Adobe Air
• Dropbox
• Skype
• QuickBooks,
TurboTax
• Python, PHP,
WebSQL
Lots of Desktop Apps:

25. Most popular?
• 550M iOS devices
• 750M Android devices
• ~500M Symbian (Nokia) devices
• ~100M Blackberry devices
Lots of Mobile Devices:

26. Most popular?
~10,000,000,000 active database instances

27. Q & A
Jay Kreibich
jay@kreibi.ch
@jkreibich
www.sqlite.org