René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Bug: On-Demand Feature Views (ODFV) on-write transformations not persisting","articleBody":"## Expected Behavior\n\nOn-write transformations in On-Demand Feature Views (ODFV) should be triggered when data is pushed to the online store using:\n\n* `store.push()`\n* `store.write_to_online_store()`\n* `materialize()`\n\nThis worked correctly in Feast version 0.43.\n\n## Current Behavior\n\nSince Feast version 0.43, only the on-read transformations are triggered. On-write transformations do not update the online store as expected - the values remain `None`. The tested versions are  0.43,0.44,0.45,0.46,0.47,0.49 with a Python 3.10.3 venv, that contains only the dependencies of feast[redis,postgres].\n\n## Steps to Reproduce\n\nI have created a minimal repo demonstrating this issue:\n [https://github.com/j-wine/feast-odfv-user-test](https://github.com/j-wine/feast-odfv-user-test)\n\nThe repo uses a dockerized environment with:\n\n* Python 3.10\n* Feast 0.49\n\nThe test script performs:\n\n1. `push()` to FeatureViews\n2. `get_online_features()` - shows ODFV on-read works, but on-write values are `None`\n3. `write_to_online_store()` - no change for on-write values\n4. `materialize()` - still no change\n\n### Example Output on Feast 0.49:\n\n```\nstep 1: Push to basic FeatureViews\n\nstep 2: get_online_features post Push\nproduct_id customer_id price_plus_revenue revenue_plus_one price_plus_rev\n0 58 74 None None 50.0\n\nstep 3: write_to_online_store into basic feature view\nres write_to_online:\nproduct_id customer_id price_plus_revenue revenue_plus_one price_plus_rev\n0 58 74 None None 50.0\n\nStep 3: materialization\n...\nStep 4: get_online_features post materialization\nproduct_id customer_id price_plus_revenue revenue_plus_one price_plus_rev\n0 58 74 None None 50.0\n\nComparison Write-Time vs. Read-Time ODFV\nprice_plus_revenue: Missing (value: None)\nrevenue_plus_one: Missing (value: None)\n```\n\n### Behavior in Feast 0.43:\n\nRunning the same test script with Feast 0.43 produces correct results - on-write transformations populate values properly. (Except for an old bug when using more than one entity in a fsv)\n\n## Specifications\n\n* Version: 0.49 \n* Platform: Docker, Python 3.10.13, Ubuntu LTS / Ubuntu WSL\n* Subsystem: ODFV on-write transformations\n\n## Possible Solution\n\nSuspected cause (based on discussion with Francisco and my debugging):\n\n* Integration tests might not fully cover this case.\n* Potential gap in unit tests for on-write transformations.\n\n\n## Additional Context\nFrancisco confirmed unit tests pass but suspects an edge case.","author":{"url":"https://github.com/jfw-ppi","@type":"Person","name":"jfw-ppi"},"datePublished":"2025-06-07T17:38:28.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/5430/feast/issues/5430"}