Perf Test for CoreData, SwiftData and Realm

Comparing the performance characteristics of Realm, SwiftData and CoreData.

Code accompanying the Emerge Tools blog article: SwiftData vs Realm: Performance Comparison by Jacob Bartlett.

Original repositoy: https://github.com/jacobsapps/RealmVsSwiftData

Michal Tsai's coverage: https://mjtsai.com/blog/2024/06/24/swiftdata-vs-realm-performance-comparison/

Issues

• UUID init is superfluous in all but Realm? CD/SQLite can do the primary keys.
• Delete all users could be just a database table drop/recreate?

Links

• SwiftData vs Realm: Performance Comparison
• RealmVsSwiftData original repository
• Storages
  • Realm by MongoDB
  • SwiftData by Apple
  • Core Data by Apple
    • ManagedModels) by Helge Heß, access Core Data in a SwiftData like fashion
  • Lighter.swift by Helge Heß, direct SQLite access

Numbers (Simulator)

M2 Mac Mini Pro, Xcode 16 b2, running in simulator Note: Core Data in the simulator seems to be about 40⨯ slower than on device!

• SwiftData and CoreData can grow big, e.g. SwiftData >6GB of RAM for the 1m user inserts, or CoreData >2GB of RAM for the "complex" 100k run.
• SwiftData w/ 1m re-running w/ the fixed non-upsert implementation

Summary simple create, in seconds:

Count	SwiftData	CoreData	Realm	Lighter
100	0.02	0.01	0.003	-
1,000	0.10	0.02	0.03	-
10,000	2.02	0.62	0.07	-
100,000	165.10	58.87	0.52	7.85
1,000,000	(10333.91)	4749.45	5.05	-
2,000,000	-	-	9.74	-

Summary complex create, in seconds:

• the Core Data numbers look odd compared to SwiftData, maybe doing sth wrong here

Count	SwiftData	CoreData	Realm
100	0.11	8.04	0.01
1,000	1.14	81.11	0.06
10,000	46.49	826.98	0.39
100,000	3835.28	8918.96	3.66
200,000	18408.65	19687.10	7.10
1,000,000	-	-	37.35

Simple User Objects

💽 ===============
💽 SwiftData: 100 Simple Objects
===============
💽 User instantiation: 0.0031
💽 Create users: 0.0166
0 users named Jane
💽 Fetch users named `Jane` in age order: 0.0021
0 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0002
💽 DB file size: 0.07 MB
💽 Delete all users: 0.0009

💽 ===============
💽 SwiftData: 1.000 Simple Objects
===============
💽 User instantiation: 0.0059
💽 Create users: 0.0989
0 users named Jane
💽 Fetch users named `Jane` in age order: 0.0005
0 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0004
💽 DB file size: 0.08 MB
💽 Delete all users: 0.0029

💽 ===============
💽 SwiftData: 10.000 Simple Objects
===============
💽 User instantiation: 0.0577
💽 Create users: 2.0238
4 users named Jane
💽 Fetch users named `Jane` in age order: 0.0029
4 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0080
💽 DB file size: 0.18 MB
💽 Delete all users: 0.0217

💽 ===============
💽 SwiftData: 100.000 Simple Objects
===============
💽 User instantiation: 0.5708
💽 Create users: 165.1004 (2:45min)
26 users named Jane
💽 Fetch users named `Jane` in age order: 0.0480
26 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.1953
💽 DB file size: 11.01 MB
💽 Delete all users: 0.2946

💽 ===============
💽 SwiftData: 1.000.000 Simple Objects
===============
💽 User instantiation: 5.5942
💽 Create users: 10333.9109 (~2:52h)
237 users named Jane
💽 Fetch users named `Jane` in age order: 1.9051
237 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 170.9562
💽 DB file size: 110.82 MB
💽 Delete all users: 16.4258

💽 ===============
💽 CoreData: 100 Simple Objects
===============
💽 User instantiation: 0.0010
💽 Create users: 0.0057
0 users named `Jane`
💽 Fetch users named `Jane` in age order: 0.0006
0 users named `Jane` being renamed to `Wendy`
0 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0002
💽 DB file size: 0.03 MB
💽 Delete all users: 0.0002

💽 ===============
💽 CoreData: 1.000 Simple Objects
===============
💽 User instantiation: 0.0021
💽 Create users: 0.0178
0 users named `Jane`
💽 Fetch users named `Jane` in age order: 0.0002
0 users named `Jane` being renamed to `Wendy`
0 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0003
💽 DB file size: 0.03 MB
💽 Delete all users: 0.0008

💽 ===============
💽 CoreData: 10.000 Simple Objects
===============
💽 User instantiation: 0.0206
💽 Create users: 0.6172
0 users named `Jane`
💽 Fetch users named `Jane` in age order: 0.0012
0 users named `Jane` being renamed to `Wendy`
0 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0013
💽 DB file size: 0.03 MB
💽 Delete all users: 0.0076

💽 ===============
💽 CoreData: 100.000 Simple Objects
===============
💽 User instantiation: 0.1903
💽 Create users: 58.8672 (1min)
29 users named `Jane`
💽 Fetch users named `Jane` in age order: 0.0278
29 users named `Jane` being renamed to `Wendy`
29 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0537
💽 DB file size: 7.28 MB
💽 Delete all users: 0.0971

💽 ===============
💽 CoreData: 1.000.000 Simple Objects
===============
💽 User instantiation: 1.9665
💽 Create users: 4749.4489 (~1:20h)
202 users named `Jane`
💽 Fetch users named `Jane` in age order: 0.7345
202 users named `Jane` being renamed to `Wendy`
202 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 1.4318
💽 DB file size: 72.67 MB
💽 Delete all users: 64.1758

💽 ===============
💽 Realm: 100 Simple Objects
===============
💽 User instantiation: 0.0005
💽 Create users: 0.0038
0 users named Jane
💽 Fetch users named `Jane` in age order: 0.0037
0 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0022
💽 DB file size: 0.02 MB
💽 Delete all users: 0.0012

💽 ===============
💽 Realm: 1.000 Simple Objects
===============
💽 User instantiation: 0.0021
💽 Create users: 0.0260
0 users named Jane
💽 Fetch users named `Jane` in age order: 0.0001
0 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0021
💽 DB file size: 0.12 MB
💽 Delete all users: 0.0024

💽 ===============
💽 Realm: 10.000 Simple Objects
===============
💽 User instantiation: 0.0190
💽 Create users: 0.0680
2 users named Jane
💽 Fetch users named `Jane` in age order: 0.0003
2 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0017
💽 DB file size: 1.00 MB
💽 Delete all users: 0.0028

💽 ===============
💽 Realm: 100.000 Simple Objects
===============
💽 User instantiation: 0.1950
💽 Create users: 0.5171
23 users named Jane
💽 Fetch users named `Jane` in age order: 0.0010
23 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0053
💽 DB file size: 6.00 MB
💽 Delete all users: 0.0094

💽 ===============
💽 Realm: 1.000.000 Simple Objects
===============
💽 User instantiation: 1.6582
💽 Create users: 5.0533
204 users named Jane
💽 Fetch users named `Jane` in age order: 0.0134
204 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0129
💽 DB file size: 55.33 MB
💽 Delete all users: 0.0287

💽 ===============
💽 Realm: 2.000.000 Simple Objects
===============
💽 User instantiation: 3.2950
💽 Create users: 9.7441
410 users named Jane
💽 Fetch users named `Jane` in age order: 0.0206
410 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0319
💽 DB file size: 112.11 MB
💽 Delete all users: 0.0446

💽 ===============
💽 Lighter: 1.000.000 Simple Objects
===============
💽 User instantiation: 0.4484
💽 Create users: 7.8463
💽 Create index: 0.3628
218 users named Jane
💽 Fetch users named `Jane` in age order: 0.0016
218 users renamed to `Wendy`
💽 Rename users named `Jane` to `Wendy`: 0.0100
💽 DB file size: 79.65 MB
💽 Delete all users: 10.0460

Complex Student/School/Grade Objects

💽 ===============
💽 SwiftData: 100 Complex Objects
===============
💽 Student instantiation: 0.0058
💽 Create students: 0.1101
3 students with an A* in Physics
💽 Read students with A* in Physics: 0.0021
💽 Fail the cheating Maths students: 0.0005
💽 DB file size: 0.73 MB
💽 Delete all students: 0.0034

💽 ===============
💽 SwiftData: 1.000 Complex Objects
===============
💽 Student instantiation: 0.0367
💽 Create students: 1.1428
43 students with an A* in Physics
💽 Read students with A* in Physics: 0.0185
💽 Fail the cheating Maths students: 0.0170
💽 DB file size: 1.13 MB
💽 Delete all students: 0.0194

💽 ===============
💽 SwiftData: 10.000 Complex Objects
===============
💽 Student instantiation: 0.3201
💽 Create students: 46.4866
390 students with an A* in Physics
💽 Read students with A* in Physics: 1.4684
💽 Fail the cheating Maths students: 0.7190
💽 DB file size: 7.83 MB
💽 Delete all students: 0.2226

💽 ===============
💽 SwiftData: 100.000 Complex Objects
===============
💽 Student instantiation: 3.2821
💽 Create students: 3835.2785 (>1h)
3951 students with an A* in Physics
💽 Read students with A* in Physics: 107.9419
💽 Fail the cheating Maths students: 76.1356
💽 DB file size: 71.50 MB
💽 Delete all students: 11.1390

💽 ===============
💽 SwiftData: 200.000 Complex Objects
===============
💽 Student instantiation: 6.7132
💽 Create students: 18408.6534 (>5h)
7948 students with an A* in Physics
💽 Read students with A* in Physics: 419.5726
💽 Fail the cheating Maths students: 314.0178
💽 DB file size: 174.85 MB
💽 Delete all students: 35.4886

💽 ===============
💽 CoreData: 100 Complex Objects
===============
💽 Student instantiation: 0.0046
Created 100 students.
💽 Create students: 8.0364      // this looks odd?
3 students with an A* in Physics
💽 Read students with A* in Physics: 0.0760
De-graded 0 students.
💽 Fail the cheating Maths students: 0.0960
💽 DB file size: 0.05 MB
💽 Delete all students: 0.1633

💽 ===============
💽 CoreData: 1.000 Complex Objects
===============
💽 Student instantiation: 0.0194
Created 1000 students.
💽 Create students: 81.1106
42 students with an A* in Physics
💽 Read students with A* in Physics: 0.3628
De-graded 0 students.
💽 Fail the cheating Maths students: 0.0963
💽 DB file size: 0.05 MB
💽 Delete all students: 0.1683

💽 ===============
💽 CoreData: 10.000 Complex Objects
===============
💽 Student instantiation: 0.1919
Created 10000 students.
💽 Create students: 826.9841 (~14min)
398 students with an A* in Physics
💽 Read students with A* in Physics: 3.0860
De-graded 0 students.
💽 Fail the cheating Maths students: 0.0997
💽 DB file size: 4.79 MB
💽 Delete all students: 0.2481

💽 ===============
💽 CoreData: 100.000 Complex Objects
===============
💽 Student instantiation: 1.9152
Created 100000 students.
💽 Create students: 8918.9621 (~2:28h)
3877 students with an A* in Physics
💽 Read students with A* in Physics: 32.5651
De-graded 0 students.
💽 Fail the cheating Maths students: 0.1078
💽 DB file size: 48.77 MB
💽 Delete all students: 104.8843

💽 ===============
💽 CoreData: 200.000 Complex Objects
===============
CoreData: debug: PostSaveMaintenance: incremental_vacuum with freelist_count - 28 and pages_to_free 15
💽 Student instantiation: 3.8674
CoreData: debug: PostSaveMaintenance: fileSize 103580952 greater than prune threshold
CoreData: annotation: PostSaveMaintenance: wal_checkpoint(TRUNCATE) 
Created 200000 students.
💽 Create students: 19687.0992
7817 students with an A* in Physics
💽 Read students with A* in Physics: 73.8052
De-graded 0 students.
💽 Fail the cheating Maths students: 0.1214
💽 DB file size: 98.21 MB
CoreData: debug: PostSaveMaintenance: fileSize 99308512 greater than prune threshold
CoreData: debug: PostSaveMaintenance: incremental_vacuum with freelist_count - 25098 and pages_to_free 25055
CoreData: annotation: PostSaveMaintenance: wal_checkpoint(TRUNCATE) 
💽 Delete all students: 237.7696

💽 ===============
💽 Realm: 100 Complex Objects
===============
💽 Student instantiation: 0.0028
💽 Create students: 0.0121
14 students with an A* in Physics
💽 Read students with A* in Physics: 0.0043
💽 Fail the cheating Maths students: 0.0025
💽 DB file size: 123.56 MB
💽 Delete all students: 0.0023

💽 ===============
💽 Realm: 1.000 Complex Objects
===============
💽 Student instantiation: 0.0129
💽 Create students: 0.0551
137 students with an A* in Physics
💽 Read students with A* in Physics: 0.0016
💽 Fail the cheating Maths students: 0.0023
💽 DB file size: 123.56 MB
💽 Delete all students: 0.0035

💽 ===============
💽 Realm: 10.000 Complex Objects
===============
💽 Student instantiation: 0.1318
💽 Create students: 0.3925
1386 students with an A* in Physics
💽 Read students with A* in Physics: 0.0158
💽 Fail the cheating Maths students: 0.0024
💽 DB file size: 123.56 MB
💽 Delete all students: 0.0142

💽 ===============
💽 Realm: 100.000 Complex Objects
===============
💽 Student instantiation: 1.3089
💽 Create students: 3.6597
13292 students with an A* in Physics
💽 Read students with A* in Physics: 0.1867
💽 Fail the cheating Maths students: 0.0063
💽 DB file size: 123.56 MB
💽 Delete all students: 0.1508

💽 ===============
💽 Realm: 200.000 Complex Objects
===============
💽 Student instantiation: 2.4842
💽 Create students: 7.0981
26652 students with an A* in Physics
💽 Read students with A* in Physics: 0.3773
💽 Fail the cheating Maths students: 0.0062
💽 DB file size: 123.56 MB
💽 Delete all students: 0.2842

💽 ===============
💽 Realm: 1.000.000 Complex Objects
===============
💽 Student instantiation: 12.5471
💽 Create students: 37.3543
132480 students with an A* in Physics
💽 Read students with A* in Physics: 2.0903
💽 Fail the cheating Maths students: 0.0149
💽 DB file size: 364.42 MB
💽 Delete all students: 1.3790