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Advisory: Issues in Serialized Data Feature – Update and Resolution

Sept 18, 2025

This advisory outlines recently identified issues in the Ed-Fi ODS/API platform's Serialized Data feature. The identified issues affect the accuracy and consistency of serialized representations.

The optional Serialized Data feature was introduced to enhance performance by storing resource data in a serialized binary format. To ensure data integrity during cascading key changes, the feature compares the LastModifiedDate of the resource table with the LastModifiedDate embedded in the binary data to determine whether the serialized data is current.

Issue 1: Triggers on Aggregate Root Tables with Volatile Foreign Keys​

  • Problem: Triggers on aggregate root tables do not update the LastModifiedDate when foreign key values change due to cascading updates.
  • Impact: The API incorrectly assumes the serialized data is current, even when foreign key changes should invalidate it.
  • Resolution: Trigger logic has been revised to ensure LastModifiedDate is updated appropriately when foreign keys change.

Issue 2: PUT Logic and Key Change Discrepancy​

  • Problem: When identity fields are modified via PUT, the two-step update process causes a mismatch between the LastModifiedDate on the record and the serialized data, falsely marking the serialized data as stale.

    • Step 1: Entity is updated with general changes, including LastModifiedDate.
    • Step 2: Key change is applied separately.

  • Impact: Incorrect stale data determination subverts the serialized data optimization.

  • Resolution: LastModifiedDate is now aligned with the serialized data after a key change, allowing the serialized version of the resource to be reused rather than rebuilt.

Issue 3: HREF Resolution in Child Items with Unified Keys​

  • Problem: Child items with unified keys fail to resolve href values correctly.
  • Impact: Serialized output contains placeholder GUIDs (e.g., 0s) instead of valid references.
  • Resolution: Serialization logic has been updated to correctly resolve unified foreign keys in the context of the parent entity.

Patch Availability​

Fixes have been released in a patch for ODS/API v7.3.

NuGet Packages​

  • Refer 7.3 Binary Releases for updated packages.
  • To install:
    • Rename the download by changing the extension .nupkg to .zip.
    • Open the zip file, extract the DLL files.
    • Copy them into the binary directory for your installation.

Source Code Releases​

Updated source code is available at:

Review the linked tags above and cherry-pick the commits included in the release.

note

Database changes are required on the Operational Data Store. Review the relevant commit and apply updates. MetaEd extension users may need to update DDL scripts.

info

The Serialized Data feature is optional and can be disabled. To disable, set ApiSettings:Features:SerializedData configuration to false. Refer to the Configuration Details page.