Failed to start DataStore - DataStoreException: "Row too big to fit into CursorWindow"

[NoahRazzaq]

Description

I encountered an issue with AWS Amplify DataStore in Flutter where querying models results in the following error when launching the app for the second time in debug mode. However, I do not experience this issue in the production environment.

DataStoreException { "message": "Failed to start DataStore.", "recoverySuggestion": "Retry.", "underlyingException": "DataStoreException{message=Timed out while starting to observe storage changes., cause=java.lang.RuntimeException: DataStoreException{message=Error in querying the model., cause=android.database.sqlite.SQLiteBlobTooBigException: Row too big to fit into CursorWindow requiredPos=0, totalRows=1, recoverySuggestion=See attached exception for details.}, recoverySuggestion=There is a possibility that there is a bug if this error persists.

exception: Row too big to fit into CursorWindow requiredPos=0, totalRows=1; query: SELECT PersistentRecord.id AS PersistentRecord_id, PersistentRecord containedModelClassName AS PersistentRecord_containedModelClassName, PersistentRecord.containedModelId AS PersistentRecord_containedModelId, PersistentRecord.serializedMutationData AS PersistentRecord_serializedMutationData FROM PersistentRecord LIMIT ? OFFSET ?;"

The error suggests that a row is too big to fit into SQLite's CursorWindow.

Could you provide guidance on how to handle this issue?

Categories

• Analytics
• API (REST)
• API (GraphQL)
• Auth
• Authenticator
• DataStore
• Notifications (Push)
• Storage

Steps to Reproduce

1. Create a DataStore model with large string or JSON fields.
2. Save multiple large records to DataStore.
3. Start the the app in debug mode and the stop/kill the app
4. Restart the app in debug mode (2nd launch).
5. Observe that DataStore fails to start with the error.

Screenshots

No response

Platforms

• iOS
• Android
• Web
• macOS
• Windows
• Linux

Flutter Version

3.22.1

Amplify Flutter Version

2.4.1

Deployment Method

Amplify Gen 2

Schema

[ekjotmultani]

Hi @NoahRazzaq, I'm sorry to see that you are facing this issue, thank you for taking the time to open it! I want to clarify, when you say launching for the second time, do you mean by completely terminating the app or through flutter itself (i.e. re-running it in vscode). Also, are you using simulators or physical devices, and do you notice this issue on both ios and android? Could you provide a sample schema as well?

[NoahRazzaq]

Hi @ekjotmultani
Sorry for not getting back to you sooner,I was quite busy.

To clarify, when I mentioned launching for the second time, I meant completely terminating the app and then starting debugging again (e.g., stopping the app and then clicking "Start Debugging" in VS Code).

I'm using an Android tablet.

Reproduction Model
The following is not my actual class but a reproduction of the issue.

import 'package:amplify_core/amplify_core.dart' as amplify_core;

class MyData extends amplify_core.Model {
  final int id;
  final String name;
  final double price;
  final bool isActive;
  final DateTime createdAt;
  final int quantity;
  final String category;
  final double rating;
  final bool inStock;
  final String description;
  final List<String> tags;
  final String metadata; // Large JSON stored as String
  final String brand;
  final int views;
  final String color;
  final double weight;
  final int stockCount;
  final String size;
  final bool isFeatured;
  final String sku;
  final String barcode;
  final double discount;
  final int sold;
  final String manufacturer;
  final double length;
  final double width;
  final double height;
  final String modelNumber;
  final bool isReturnable;
  final String warranty;
  final double tax;
  final int minOrderQuantity;
  final int maxOrderQuantity;
  final bool isExclusive;
  final String countryOfOrigin;
  final double shippingCost;
  final String seller;
}

The metadata field stores large JSON data, and I suspect that this is what’s causing the SQLiteBlobTooBigException when DataStore tries to process it.

Additional Info
I have recorded around 200 MyData entries in DataStore.
I provided a JSON file for you to try, which contains a sample of the metadata field.

large_metadata.json

Let me know if you need more details!

Thanks for your help!