Realm is a mobile database that uses native objects mapped to a custom database engine rather than SQLite. It allows for complex data modeling with linked objects and advanced queries. Realm prioritizes ease of use, performance, cross-platform support, advanced features like reactive patterns, and community/support. Major companies like Twitter and Starbucks use Realm for their mobile apps.

1. REALM 研究
2016/6/2
Jason

2. GITHUB

3. WHAT IS REALM?
• Realm is not an ORM, and is not built on top of
SQLite. Instead we’ve built a full database for
mobile app developers, one that uses native
objects that are dynamically mapped to a full,
custom database engine (not just a key-value
store). This allows us to provide a simple API
while even enhancing performance. With
Realm, you can model complex data, link
objects in a graph, and compose advanced
queries.

4. WHY USE REALM?
• Easy
• Realm’s primary focus has always been
ease of use. Developers tell us they switch
even large apps to Realm in hours, and save
weeks of implementation, optimization &
debugging time on an average project.

5. WHY USE REALM?
• Fast
• Realm’s ease of use doesn’t come at a
performance cost. Because of its memory
mapping, lazy loading, and custom storage
engine, Realm is usually faster than raw SQLite,
despite offering a rich object-based API. Although
we always recommend that everyone test their
own use-cases, developers usually see huge

6. WHY USE REALM?
• Cross-platform
• Realm supports Java, Objective-C, React
Native, Swift and Xamarin. You can share
Realm files across platforms, use the same
data models, and write similar business logic
on all platforms. For debugging, .realm files
can be opened with the Realm Browser.

7. WHY USE REALM?
• Advanced
• Realm objects are always up-to-date with the
underlying data, making it trivial to follow reactive
patterns or a unidirectional data flow. You can link
Realm objects in graphs, use an advanced query
language, rely on built-in AES256 encryption, and
even easily integrate Realm data into your UI
through optional add-ons.

8. WHY USE REALM?
• Trusted
• Have a large app or a large userbase?
Realm’s the database for you. We’re already
trusted in production by banks and
healthcare providers, and proven across
complex enterprise apps and #1 hits on both
the Apple App Store and Google Play Store.

9. WHY USE REALM?
• Community-driven
• Realm is built in the open on GitHub.
Features are prioritized based on user
requests and we welcome contributions. We
have over 12,000 stars on GitHub, and
beyond the core projects, our community has
already been building hundreds of apps,

10. WHY USE REALM?
• Supported
• Realm prioritizes support and bug fixes
above all else. You can get answers about
your database directly from the people that
build & maintain it, via Stack Overflow,
GitHub, or Twitter.

11. WHO IS USING REALM?
• Twitter
• Starbucks
• Alibaba
• Budweiser
• SAP
• Rite Aid

12. 優點
• 入門門檻低
• 據說性能好一些
• 沒有需要架構Context那種煩人的東西
• 支持NSPredicate
• 很簡單的使用多個存儲文件
• 技術支持

13. 缺點
• 關聯關係弱的一逼
• 強制內省容錯機制導致存儲文件不斷變大
• 增加包體積
• 核心代碼目前閉源

14. COREDATA 優點
• 官方支持&& 親兒子
• 帶圖形化的Model編輯
• 強大的關聯關係
• 強大的查詢
• 精細化的通知

15. COREDATA 缺點
• 入門門檻高
• 需要一些工具才感覺好使
• Context
• 多個持久化文件很麻煩

16. 參考官方
• https://github.com/realm/realm-cocoa
• https://realm.io/
• Introducing Realm React Native
https://realm.io/news/introducing-realm-react-native/
• 13,949 Commits and 6,148 Closed Issues Later:
Thank You for Helping Realm Reach 1.0
https://realm.io/news/realm-1.0/

17. 參考教學
• CoreData VS Realm：iOS 持久化哪家強？
http://www.cocoachina.com/ios/20160127/15133.html
• Core Data, FMDB, Realm 性能測試
http://suree.org/2015/09/29/DatabaseThink/
• iOS 數據庫比較：SQLite vs. Core Data vs. Realm
http://www.oschina.net/translate/ios-databases-sqllite-vs-core-data-vs-
realm
• iOS：選擇Realm 而不是CoreData
http://swift.gg/2015/12/08/ios-realm-instead-of-coredata/

18. • CoreData VS Realm
http://iiiyu.com/2016/01/19/CoreData-VS-
Realm/