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
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)
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
