This document discusses various ORM libraries and compares their performance. It introduces ORMlite, GreenDAO, Realm, and native SQLite as options for interacting with databases in Android. GreenDAO is highlighted as significantly faster than ORMlite for write and read operations. Performance tests show GreenDAO inserting over 100k records around 7 seconds on average, while ORMlite took over 40 seconds. Realm was also faster than ORMlite but slower than GreenDAO. The document encourages using more performant options like GreenDAO and Realm over ORMlite for database work in Android.

1. ORM各library效能分析與使用
（硬湊的主題） https://goo.gl/iLOCYN
Takuma

2. ORM Library
1. ormlite
2. greendao
3. realm
4. DBFlow
5. ActiveAndroid

3. ORM Library
1. ormlite
2. greendao
3. realm
4. DBFlow
5. ActiveAndroid

4. 何謂ORM？
Object Relational Mapping

5. 何謂ORM？
Object Relational Mapping
Object Role Modeling

6. 何謂ORM？
Object Relational Mapping
Object Role Modeling
Optical Remote Module

7. 何謂ORM？
Object Relational Mapping
Object Role Modeling
Optical Remote Module
……

8. 何謂ORM？
Object Relational Mapping
Object Role Modeling
Optical Remote Module
……

9. 何謂ORM？
Object Relational Mapping
Object Role Modeling
Optical Remote Module
……

10. 總之他就是個Database概念！！！

11. 進入正題

12. 就算不用ORM library
也沒關係
我們還有原生的SQLite！

13. @Override
public void onCreate(SQLiteDatabase db) {
String DATABASE_CREATE_TABLE =
"create table newMemorandum("
+ "_ID INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,"
+ "date VARCHAR,"
+ "note VARCHAR,"
+ "pw VARCHAR,"
+ "reminder INT,"
+ "type VARCHAR,"
+ "memo VARCHAR"
+ ")";
db.execSQL(DATABASE_CREATE_TABLE);
}
SQLite原生寫法

14. 我很懶！＝懶是工程師的美德

15. 我很懶＝懶是工程師的美德

16. 我很懶 == 懶是工程師的美德

17. @Override
public void onCreate(SQLiteDatabase sqliteDatabase, ConnectionSource connectionSource) {
try {
TableUtils.createTableIfNotExists(connectionSource, Character.class);
} catch (SQLException e) {
e.printStackTrace();
}
}
ormlite寫法

18. public static void main(String args[]) throws Exception {
Schema schema = new Schema(3, "com.takumalee.ormcomparison.database.greendao.dao");
createTable(schema);
generateDaoFiles(schema);
}
private static void createTable(Schema schema){
//一個Entity 對應一個 DB table
Entity point = schema.addEntity("Character");
//add table column
point.addIdProperty();
point.addStringProperty("careers").notNull();
point.addStringProperty("attributes").notNull();
}
GreenDao寫法（一）

19. GreenDao寫法（二）
private static void generateDaoFiles(Schema schema){
try {
DaoGenerator generator = new DaoGenerator();
//建立到指定目錄
generator.generateAll(schema, "../ORMComparison/app/src/main/java/");
} catch (Exception e){
e.printStackTrace();
}
}

20. ……
Realm寫法

21. 事件起源

22. Realm官方表示

23. 有效能就是任性！

24. 再跟我大聲說一次：有效能就是......

26. ormlite vs greenDao
GreenDao is much faster than ORMLite. It is roughly:
●3X faster at writing large numbers of objects.
●50% faster at reading in all 10000 entries in a single table.
●2X to 3X faster at an indexed read of a single row (though both were very fast).
●15X faster at doing a LIKE search for 100 records in a 10000 entry table.

27. WTF？

28. Google Play（https://goo.gl/tnirTh）
Github（https://goo.gl/RJqYu4）
Blog（http://goo.gl/IWR5Ih）
偷渡自己的記帳App:MMM
（https://goo.gl/Lg5ZdX）
ORM 效能分析實作

29. Insert（錯誤條件・IfNotExist）
ormlite:
- 45.9sec per 100k
greeDAO:
- 7.3sec per 100k
realm:
- 18.5sec per 100k

30. Insert（ormlite拿掉IfNotExist，realm拿掉Primary key）
ormlite:
- 14.1sec per 100k
greeDAO:
- 7.1sec per 100k
realm:
- 8.6sec per 100k

31. Query（多做了Data Access Object）
ormlite:
- 20.3sec per 100k
greeDAO:
- 11.2sec per 100k
realm:
- 287ms per 100k

32. Emulator Demo

33. Mobile Demo

34. ありがとう
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