Fetching data with relationships directly faults the relationships even when not accessed

Question

Created May ’25

Replies 7

Boosts 1

Participants 3

I am using SwiftData to model my data. For that i created a model called OrganizationData that contains various relationships to other entities. My data set is quite large and i am having a big performance issue when fetching all OrganizationData entities. I started debugging and looking at the sql debug log i noticed that when fetching my entities i run into faults for all relationships even when not accessing them.

Fetching my entities:

let fetchDescriptor = FetchDescriptor<OrganizationData>()
let context = MapperContext(dataManager: self)
let organizations = (try modelContainer.mainContext.fetch(fetchDescriptor))

Doing this fetch, also fetches all relationships. Each in a single query, for every OrganizationData entity.

CoreData: annotation: to-many relationship fault "relationship1" for objectID 0x8aa5249772916e00 <x-coredata://B891FCEB-DF16-4E11-98E6-0AFB5D171A81/OrganizationData/p3869> fulfilled from database.  Got 9 rows
CoreData: annotation: to-many relationship fault "relationship2" for objectID 0x8aa5249772916e00 <x-coredata://B891FCEB-DF16-4E11-98E6-0AFB5D171A81/OrganizationData/p3869> fulfilled from database.  Got 0 rows
CoreData: annotation: to-many relationship fault "relationship3" for objectID 0x8aa5249772916e00 <x-coredata://B891FCEB-DF16-4E11-98E6-0AFB5D171A81/OrganizationData/p3869> fulfilled from database.  Got 0 rows
CoreData: annotation: to-many relationship fault "relationship4" for objectID 0x8aa5249772916e00 <x-coredata://B891FCEB-DF16-4E11-98E6-0AFB5D171A81/OrganizationData/p3869> fulfilled from database.  Got 0 rows
CoreData: annotation: to-many relationship fault "relationship5" for objectID 0x8aa5249772916e00 <x-coredata://B891FCEB-DF16-4E11-98E6-0AFB5D171A81/OrganizationData/p3869> fulfilled from database.  Got 0 rows
CoreData: annotation: to-many relationship fault "relationship6" for objectID 0x8aa5249772916e00 <x-coredata://B891FCEB-DF16-4E11-98E6-0AFB5D171A81/OrganizationData/p3869> fulfilled from database.  Got 0 rows
CoreData: annotation: to-many relationship fault "relationship7" for objectID 0x8aa5249772916e00 <x-coredata://B891FCEB-DF16-4E11-98E6-0AFB5D171A81/OrganizationData/p3869> fulfilled from database.  Got 1 rows
CoreData: annotation: to-many relationship fault "relationship8" for objectID 0x8aa5249772916e00 <x-coredata://B891FCEB-DF16-4E11-98E6-0AFB5D171A81/OrganizationData/p3869> fulfilled from database.  Got 0 rows
CoreData: annotation: to-many relationship fault "relationship9" for objectID 0x8aa5249772916e00 <x-coredata://B891FCEB-DF16-4E11-98E6-0AFB5D171A81/OrganizationData/p3869> fulfilled from database.  Got 0 rows

The relationships are all defined the same

@Relationship(deleteRule: .cascade, inverse: \EntityData1.organization)
var relationship1: [EntityData1] = []

Am i missing something? As far as i understood relationships are lazy and should only be faulted when accessing the property. But doing the fetch as described above already causes a query to happen, making the fetch take very long when using a large data set.

Boost

Answer 1

dasdasda OP

May ’25

Just as an additional information even adding 'propertiesToFetch' to the fetchDescriptor makes no difference

var fetchDescriptor = FetchDescriptor<OrganizationData>()
fetchDescriptor.propertiesToFetch = [\.id]
let organizations = (try? modelContainer.mainContext.fetch(fetchDescriptor))

0

Answer 2

StephanKolev OP

May ’25

i have the same issue

1

Answer 3

dasdasda OP

May ’25

Some feedback would be appreciated. I also created a simple test app that reproduces this issue.

0

Answer 4

DTS Engineer OP

Apple

4w

@dasdasda Would you mind to make your test project available? I'd try to reproduce the issue and see what happens. Your post can contain a link to where your test project is hosted.

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.

0

Answer 5

dasdasda OP

4w

Here is a simple test project:

https://github.com/GNiewoehner/swiftdata-test-app

On start it creates some dummy data, and fetches them without accessing any relationships. The logs are printed to the console.

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Answer 6

dasdasda OP

3w

@DTS Engineer Do you have any update regarding the issue?

0

Answer 7

dasdasda OP

3d

Any update?

0