What's in a Mobile Database?

Transcript

1. WHAT’S IN A MOBILE DATABASE?
2. SAMUEL GIDDINS REALM.IO
3. Show of hands: WHO’S USED A DATABASE?
4. LET’S NAME SOME
5. MOST OF THOSE ARE SERVER DATABASES
7. SQLITE THE STATUS QUO
8. ▸ Single-threaded ▸ Dynamically-typed ▸ Weakly-typed ▸ Designed in 2000
9. WHAT ARE OUR CONSTRAINTS?
10. ▸ Running on a device ▸ Can’t update database code on a whim ▸ Little RAM ▸ Relatively few CPU cores ▸ Multiple processes ▸ Long-running use of data
11. WHAT DO WE WANT TO OPTIMIZE FOR?
12. ▸ Querying ▸ Reading values ▸ Maintainable API ▸ Safe Migrations ▸ Static + Dynamic Schemas
13. THE GOALS
14. ▸ Cross-platform ▸ Memory-mapped ▸ Thread-safe ▸ Object-oriented ▸ Blazing fast ▸ Sane interface
15. CROSS PLATFORM
16. People build services that need to run on multiple platforms. Their database should reflect this.
17. MEMORY MAPPING
18. void *mmap( void *addr, size_t length, int prot, int flags, int fd, off_t offset ); This function is magical.
19. Blur the line between in-memory and on-disk to get the best of both worlds. Take advantage of optimizations in the kernel and let it do the hard work for you.
20. THREAD SAFETY
21. THREAD SAFETY PERHAPS THE MOST LOADED WORD IN CS
22. WELL-DEFINED THREADING MODEL ▸ What can be passed between threads? ▸ How easily can I isolate things that can’t be?
23. Built with speed & safety in mind: ▸ No reader lock ▸ Allow concurrent reading & writing ▸ Let the user know when they violate the threading contract
24. OBJECT-ORIENTED API
25. ▸ First-class model objects ▸ Support for persisted + in memory objects ▸ No invisible web of classes
26. BLAZING FAST
27. WHY SHOULD OBJECTS AND THE DATABASE EVER GROW APART?
28. WHY SHOULD OBJECTS AND THE DATABASE EVER GROW APART? OR WHERE ORMS WENT WRONG
29. ▸ Lazily create objects in memory ▸ Access & set values directly in the DB ▸ Optimized query engine
30. SANE API
31. ▸ What do I need a reference to? ▸ Platform coherence ▸ Isolate DB interaction ▸ Make it impossible to mess up
32. LET’S RECAP
33. ▸ Cross-platform ▸ Memory-mapped ▸ Thread-safe ▸ Object-oriented ▸ Blazing fast ▸ Sane interface
34. SOUNDS A LOT LIKE THE DREAM, RIGHT?
35. Make persistence just another aspect of your data, instead of a whole convoluted system.
36. ⾠ This might not be the approach for everyone. Take a look at the goals, and see if they align with your own.
37. My company, Realm, is working towards building a database that hits these bullet points. I’m not here to sell you on Realm. But building something that mirrors those goals is why we exist.
38. EXAMPLES?
39. Available now on Speaker Deck. https://speakerdeck.com/segiddins/whats-in-a-mobile-database
40. db.objects(Question).map { $0.ask }
41. SAMUEL GIDDINS REALM.IO @SEGIDDINS