This document discusses migrating an Android app's database from SQLite to Realm. It describes how the author modified their webtoon app source code on GitHub to replace SQLite components like SqlBrite with Realm and related libraries. Performance tests showed improvements like reduced insertion and search times when using Realm compared to the original SQLite implementation. Some challenges mentioned include Realm's larger APK size, potential out of memory errors with large transactions, and ensuring compatibility with different Realm versions. Overall, the document recommends considering Realm from the beginning of a new project rather than migrating later.

1. SqliteToRealm
작은 경험 이야기

2. Who?
Pluu / Pluulove
Android Developer
http://pluu.github.io/

3. Screen

4. Why?
● 웹툰 앱 소스 GitHub 공개
● 내 소스인데 엉망이다
● 바꿔보고 싶은 걸 바꿔보자
그냥!!

5. Modify
● jsoup
● butterknife
● glide
● sqlbrite
● rxandroid
● okhttp
● jsoup
● butterknife
● glide
● realm
● otto
● rxandroid

6. Save
● Favorite Info
● Read Info
Favorite
Service Name : String
Toon ID : String
Read
Service Name : String
Toon ID : String
Episode ID : String

7. Sqlbrite
● by square
● SQLiteOpenHelper + Reactive
○ A lightweight wrapper around SQLiteOpenHelper which introduces reactive stream semantics to
SQL operation

8. Sqlbrite
Rx Square
믿고 쓰는dalinaum 님
최정열 님

9. Sqlbrite Code
BriteDatabase db = sqlBrite.wrapDatabaseHelper(openHelper);
Observable<Query> users = db.createQuery("users", "SELECT * FROM users");
users.subscribe(new Action1<Query>() {
@Override public void call(Query query) {
Cursor cursor = query.run();
// TODO parse data...
}
});

10. Realm
● Core NDK
● Realm != Sqlite
● Sqlite Migration Guide X
○ Realm 0.84.2

11. SqliteToRealm
● https://github.
com/jixaCo/Sqlit
eToRealm
● https://realm.
io/addons/ > Java
> Tools >
SqliteToRealm

12. SqliteToRealm.java
public void pushSynonymsToWords() {
SqliteHelper dbs = SqliteHelper.getInstance();
RealmHelper dbr = RealmHelper.getIntance();
List<Word> rawWords = getAllRawWords();
List<List<String>> records = dbs.getRecords("synonym");
List<IntPair> synonyms = new ArrayList<>();
for(List<String> record : records){
if(null == record.get(0) || null == record.get(1))
continue;
IntPair pair = new IntPair(Integer.parseInt(record.get(0)),Integer.parseInt(record.get(1)));
synonyms.add(pair);
}
dbr.addSynonymToWords(synonyms);
}

13. SqliteToRealm
Sqlite Realm
● Open Sqlite
● Get Data
● Close Sqlite
● Realm.getInsatance(Context)
● beginTransaction()
● Add Data
● commitTransaction()

14. Um ...
● Realm 사용
○ SPEED
○ ORM
● 기존 sqlite 관련 파일을 지울 수 없음
○ SQLiteOpenHelper
○ Item Class
● 한국 페이지에는 부재인 ADD-ON 페이지

15. Extend Um ...
● APK SIZE
○ ABI Split 으로 해결 가능
○ Reducing your Android APK size When Using Native Libraries
● 큰 데이터 (수만 건)
○ 트랜잭션에서 처리하는 단위가 큰 경우 OOM 발생
○ 100~200 단위 처리
● Realm version에 맞는 Proguard 처리
Link : Twitterクライアントの内部DBをSQLiteからRealmに移行したときのノウハウまとめ
Link : Realm導入によるAPK肥大化を防ぐ(Split APK)

16. Extend Um ...
● Insert, 20 Count
○ 150ms → 100ms
● Search, 4 Count
○ 14ms → 8ms or 17ms → 10ms or or or
● Insert, 16 Count (62kb)
○ 97ms → 38ms
Link : Twitterクライアントの内部DBをSQLiteからRealmに移行したときのノウハウまとめ

17. recommended
처음부터 Realm
● Realm != Sqlite
Rx + Preference
● 초기 작업 + 1
● 실행 시 SqliteToRealm 필요
● Preference 에 Flag 등록

18. - End -