Introduction to SQLite: The Most Popular Database in the World
- 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