Advanced Core Data

Transcript

1. CORE DATA LEE SING JIE
2. ARDUINO…
3. UNDERSTANDING CORE DATA IN DEPTH
4. UNDERSTANDING CORE DATA IN DEPTH
5. GUI BROWSER
6. COMMAND LINE BROWSER $ sqlite3 /Users/singjie/present/ main-25142226 SQLite version 3.8.5 2014-08-15 22:37:57 Enter ".help" for usage hints. sqlite>
7. Z_METADATA
8. Z_METADATA - PLIST
9. Z_PRIMARYKEY
10. Z_ENT
11. SUBCLASSING SHOULD YOU?
12. SUBCLASSING
13. SUBCLASSING
14. SUBCLASSING - Z_PRIMARYKEY
15. SUBCLASSING - Z_ENT
16. SUBCLASSING - Z_ENT
17. SUBCLASSING - WHAT IS INDEXING?
18. CHECKING ON QUERY’S EFFICIENCY
19. sqlite> explain query plan select * from ZBTMessage where ZMSGID = 2; 0|0|0|SEARCH TABLE ZBTMessage USING INDEX ZBTMESSAGE_ZMSGID_INDEX (ZMSGID=?) USING EXPLAIN QUERY PLAN
20. sqlite> explain query plan select * from ZBTMessage where ZMSGID = 2; 0|0|0|SEARCH TABLE ZBTMessage USING INDEX ZBTMESSAGE_ZMSGID_INDEX (ZMSGID=?) USING EXPLAIN QUERY PLAN
21. sqlite> explain query plan select * from ZBTInvite where ZINVITEID = 2; 0|0|0|SCAN TABLE ZBTInvite USING EXPLAIN QUERY PLAN
22. SUBCLASSING - Z_ENT ZBTBuzzClub - 50k rows (Z_ENT == 16) ZBTBuzzUser - 50k rows (Z_ENT == 15) ZBTBuzz - ~100k rows Indexes: ‣ Z_ENT ‣ Z_BUZZ_ID sqlite will always use Z_ENT index SELECT * from ZBTBuzz where Z_ENT = 16 AND Z_BUZZ_ID = 123;
23. SUBCLASSING - Z_ENT Indexes: ‣ Z_ENT ‣ Z_BUZZ_ID sqlite> explain query plan select * from ZBTBuzz where Z_ENT = 16 AND Z_BUZZ_ID = 123; 0|0|0|SEARCH TABLE ZBTBuzz USING INDEX ZBTBuzz_Z_ENT_INDEX (Z_ENT=?) SELECT * from ZBTBuzz where Z_ENT = 16 AND Z_BUZZ_ID = 123;
24. SUBCLASSING - Z_ENT INDEX ZBTBuzzClub - 50k rows (Z_ENT == 16) ZBTBuzzUser - 50k rows (Z_ENT == 15) ZBTBuzz - ~100k rows ZBTBuzzClub - 50k rows (Z_ENT == 16) ZBTBuzzClub - 1 row (Z_BUZZ_ID = 123) 1 2 3 SELECT * from ZBTBuzz where Z_ENT = 16 AND Z_BUZZ_ID = 123;
25. SUBCLASSING - Z_BUZZ_ID INDEX ZBTBuzzClub - 50k rows (Z_ENT == 16) ZBTBuzzUser - 50k rows (Z_ENT == 15) ZBTBuzz - ~100k rows ZBTBuzzClub - 2 rows (Z_BUZZ_ID == 123) ZBTBuzzClub - 1 row (Z_ENT == 16) 1 2 3 SELECT * from ZBTBuzz where Z_ENT = 16 AND Z_BUZZ_ID = 123;
26. SUBCLASSING - Z_ENT, Z_BUZZ_ID COMPOUND INDEX ZBTBuzzClub - 50k rows (Z_ENT == 16) ZBTBuzzUser - 50k rows (Z_ENT == 15) ZBTBuzz - ~100k rows ZBTBuzzClub - 1 row (Z_ENT == 16 && Z_BUZZ_ID == 123) 1 2 SELECT * from ZBTBuzz where Z_ENT = 16 AND Z_BUZZ_ID = 123;
27. SUBCLASSING - Z_ENT, Z_BUZZ_ID COMPOUND INDEX ZBTBuzzClub - 50k rows (Z_ENT == 16) ZBTBuzzUser - 50k rows (Z_ENT == 15) ZBTBuzz - ~100k rows ZBTBuzzClub - 1 row (Z_ENT == 16 && Z_BUZZ_ID == 123) 1 2 SELECT * from ZBTBuzz where Z_ENT = 16 AND Z_BUZZ_ID = 123;
28. HOW TO FIX?
29. SUBCLASSING ZBTBuzzClub - 50k rows (Z_ENT == 16) ZBTBuzzUser - 50k rows (Z_ENT == 15) ZBTBuzz - ~100k rows ZBTBuzzClub - 2 rows (Z_BUZZ_ID == 123) 1 2 for (id result in results) {
 if ([result isKindOfClass:[BTBuzzClub class]]) {
 …
 }
 } SELECT * from ZBTBuzz where Z_BUZZ_ID = 123;
30. IN SHORT, DON’T SUBCLASS!
31. MANAGE TYPES YOURSELF ZBTBuzz(Club) - 50k rows (Z_TYPE == BUZZCLUB) ZBTBuzz(User) - 50k rows (Z_TYPE == BUZZUSER) ZBTBuzz - ~100k rows select * from ZBTBuzz where Z_TYPE = BUZZCLUB AND Z_BUZZ_ID = 123; Compound: ‣ Z_TYPE, Z_BUZZ_ID
32. PROFILING ON THE FLY
33. PROFILING ▸ -com.apple.CoreData.SQLDebug 1
34. PROFILING 2015-11-20 10:09:48.593 BeeTalk[3579:1652444] CoreData: sql: SELECT 0, t0.Z_PK, t0.Z_OPT, t0.ZDATA, t0.ZDISPLAYINDEX, t0.ZISOUTGOING, t0.ZISWHISPER, t0.ZMEDIASTATUS, t0.ZMSGID, t0.ZREADCOUNT, t0.ZSTATUS, t0.ZTIMESTAMP, t0.ZTYPE, t0.ZWHISPERDURATION, t0.ZWHISPERSTARTTIME, t0.ZBUDDYINFO, t0.ZCHAT, t0.Z5_CHAT, t0.ZINVCHAT, t0.Z5_INVCHAT, t0.ZLASTREADCHAT, t0.Z5_LASTREADCHAT, t0.ZUSER FROM ZBTMESSAGE t0 WHERE (( t0.ZMEDIASTATUS = ? OR t0.ZMEDIASTATUS = ?) AND t0.ZTYPE = ?) 2015-11-20 10:09:48.594 BeeTalk[3579:1652444] CoreData: annotation: sql connection fetch time: 0.0002s
35. PROFILING + (void)load { #if defined DEBUG || defined INTRELEASE Method original, swizzled; original = class_getInstanceMethod(self, @selector(executeFetchRequest:error:)); swizzled = class_getInstanceMethod(self, @selector(executeFetchRequest_Swizzled:error:)); method_exchangeImplementations(original, swizzled); #endif } - (NSArray *)executeFetchRequest_Swizzled:(NSFetchRequest *)request error:(NSError *__autoreleasing *)error { NSString *logFormat = [NSString stringWithFormat:@"[%@]: %@", request.entityName, request.predicate.tracerPredicate]; CFAbsoluteTime start = CFAbsoluteTimeGetCurrent(); NSArray *results = [self executeFetchRequest_Swizzled:request error:error]; CFAbsoluteTime end = CFAbsoluteTimeGetCurrent() - start; // 100ms if (end - start > 0.1) { NSLog(@"%@", logFormat); NSParameterAssert(NO); } return results; }
36. MIGRATION WHAT REALLY HAPPENS?
37. Z_METADATA - PLIST
38. DIFFERENT HASH? BTUSER BTUSER_BAK Rename
39. DIFFERENT HASH? BTUSER_BAK BTUSER Insert
40. DIFFERENT HASH? BTUSER_BAK BTUSER
41. DIFFERENT HASH? BTUSER
42. Z_PRIMARYKEY TABLE
43. Z_PRIMARYKEY TABLE
44. Z_ENT - ALPHABETICAL ORDER 18 | BTLINKEDCONTACT 19 | BTMESSAGE
45. Z_ENT - ALPHABETICAL ORDER 18 | BTLINKEDCONTACT 19 | BTMESSAGE XX | BTMARY
46. Z_ENT 19 | BTMESSAGE 18 | BTLINKEDCONTACT XX | BTMARY
47. Z_ENT 18 | BTLINKEDCONTACT 20 | BTMESSAGE 19 | BTMARY
48. Z_PRIMARYKEY
49. HOW TO FIX?
50. Z_ENT 18 | BTLINKEDCONTACT 19 | BTMESSAGE 50 | BTZMARY
51. Z_ENT 18 | BTLINKEDCONTACT 19 | BTMESSAGE 50 | BTZMARY
52. Q&A