Talk on SQLite given at PHP Barcelona 2008

1. SQLite 3
Scott MacVicar
PHP Barcelona 2008

2. Who Am I?
• Employed by Jelsoft Enterprises Ltd
• PHP (SQLite3, imagick, svn)
• GD

3. Overview
• What is SQLite?
• Why use SQLite?
• Who uses SQLite?
• SQLite Explained
• Difference between SQLite 2 and 3
• PDO / SQLite3

4. What is SQLite?
• Embedded SQL Database Engine
• Serverless - accesses disk directly
• Single file
• Cross Platform / Architecture
• Small footprint
• Manifest typing

5. Why use SQLite?
• Zero Configuration
• Portable
• Public Domain

6. Public Domain?
May you do good and not evil.
May you find forgiveness for yourself and forgive others.
May you share freely, never taking more than you give.

7. ¿Public Domain?

8. Big SQLite Users
• Lightroom
• AIR
sqlite3 ~/Pictures/Lightroom/Lightroom Library.aglib

9. Big SQLite Users
• Mail
• Safari
• Aperture
• Core Data
• iPhone
sqlite3 ~/Library/Mail/Envelope Index
sqlite3 ~/Library/Caches/com.apple.Safari/Cache.db
sqlite3 ~/Pictures/Aperture Library.aplibrary/Aperture.aplib

10. Big SQLite Users
• Gears
• Android

11. Big SQLite Users
• Virus Information

12. Big SQLite Users
• History
• Bookmarks
• Downloads

13. Big SQLite Users
• Metadata

14. Where can SQLite be used?
• Replacement for a custom file format
• Temporary data storage (Unit Tests) - :memory:
• Alternative to enterprise DB for demo
• Local node storage
• Communication between apps
• Embedded Devices

15. Versions
• SQLite - 2.8.17
• PDO - 3.3.7 + 2.8.17 (3.6.2 in PHP 5.3)
• SQLite3 - 3.6.2, minimum is 3.3.9

16. SQLite 3
• 64-bit Rowids • Connections shared
between threads
• BLOB support
• Runtime loadable
• Improved concurrency extensions
• UTF-16 / UTF-8 • Fulltext searching
• User defined collations • ICU support
• Named bound • OS Interface
parameters

17. SQLite v2
• Smaller subset of SQL supported
• Larger file format
• Database format incompatible with v3
• No Unicode support
• No reading while writing

18. Examples
• Firefox 3.0
• Profile directory contains places.sqlite
• Schema on the next page
• iPhone SMS

19. Firefox Places Schema

20. PDO

21. SQLite3

22. Live Demo (Hopefully)

23. iPhone SMS Schema
/private/var/root/Library/SMS/sms.db
~/Library/Application Support/MobileSync/Backup

24. Custom Functions
• Define SQL Functions in PHP
• Implement missing features
• Aggregation functions

25. Function Example

26. Custom Collations
• Sorting in alphabetical ☹ ☺
order
a a
• ICU also provides this i é
functionality
u i
• Use createCollation to é ó
define comparison ó u
function

27. Fulltext Indexing

28. Fulltext Searching

29. SQLite3 Extension
SQLite3 SQLite3Stmt
open paramCount
close close
exec execute
version reset
lastInsertRowID clear
loadExtension bindValue
escapeString bindParam
prepare
query
createFunction
createAggregate
lastErrorMsg

30. SQLite3 Extension
SQLite3Result
fetchArray
reset
finalize
columnType
columnName
numColumns

31. Improving Performance
• Pragma
• cache_size
• fullfsync
• synchronous
• Shared Cache
• Use Transactions

32. Benchmarks
• Dual Xeon 3.2GHz,
2GB RAM, Centos 5
• MySQL vs SQLite
• Synthetic Benchmark -
YMMV
Original Image by Ben McLeod

33. Benchmarks - Tests
• 15 tests
• INSERT
• SELECT
• UPDATE
• DELETE
• DROP

34. Benchmarks - Insert
MySQL
10.0 SQLite 2
SQLite 3
7.5 SQLite 3 (nosync)
5.0
2.5
0
Test 1 Test 2

35. Benchmarks - Select
MySQL
10.0 SQLite 2
SQLite 3
7.5 SQLite 3 (nosync)
5.0
2.5
0
Test 3 Test 4

36. Benchmarks - Indices
MySQL
1.2 SQLite 2
SQLite 3
0.9 SQLite 3 (nosync)
0.6
0.3
0
Test 5 Test 6

37. Benchmarks - Update
MySQL
5.00 SQLite 2
SQLite 3
3.75 SQLite 3 (nosync)
2.50
1.25
0
Test 7 Test 8 Test 9

38. Benchmarks - Delete
MySQL
2.0 SQLite 2
SQLite 3
1.6
SQLite 3 (nosync)
1.2
0.8
0.4
0
Test 11 Test 12 Test 13 Test 14

39. Benchmarks - Summary
• SQLite 3 is faster in almost every test
• Using MyISAM would show faster results
• Doesn’t test concurrency

40. Converting from MySQL
• varchar, char -> text
• smallint, tinyint, int -> integer
• auto_increment -> autoincrement
• unknown types converted to text
• MySQLi functions have SQLite3 equivalents

41. Unsupported SQL - Examples
Original Image by Clive Arundell

42. Limitations
• Very large datasets
• High concurrency
• No Foreign Keys
• Nested Transactions
• Writing to Views

43. Miscellaneous
• Integrity Check
• Reclaim Unused Space
• Backup

44. Tools - SQLite Manager

45. Resources
• http://www.sqlite.org
• http://www.php.net/sqlite3
• http://pecl.php.net/sqlite3
• http://talks.macvicar.net
• https://addons.mozilla.org/en-US/firefox/
addon/5817