Bug: _materialize_odfv uses entity names instead of join keys

[max36067]

Summary

FeatureStore._materialize_odfv uses source_fv.entities (entity names) instead of source_fv.join_keys (join key column names) when building BigQuery queries. This causes materialization to fail when an entity's name differs from its join key.

Steps to Reproduce

1. Define an entity where name ≠ join key:

creator = Entity(
    name="creator",
    join_keys=["creator_id"],
    value_type=ValueType.STRING,
)

2. Define a FeatureView using that entity, and an OnDemandFeatureView sourcing from it with write_to_online_store=True.

3. Run store.materialize_incremental(...).

Expected Behavior

The generated BigQuery SQL should reference creator_id (the join key column).

Actual Behavior

The SQL references creator (the entity name), which doesn't exist as a column:

google.api_core.exceptions.BadRequest: 400 Unrecognized name: creator;
Did you mean creator_id? at [6:24]

Root Cause

In feature_store.py _materialize_odfv, two lines use .entities (names) where they should use .join_keys (column names):

• Line 1354: all_join_keys.update(source_fv.entities) → should be source_fv.join_keys
• Line 1394: join_key_columns=source_fv.entities → should be source_fv.join_keys

FeatureView.entities returns [e.name for e in entities] (entity names), while FeatureView.join_keys returns [e.name for e in self.entity_columns] (actual column names). When these differ, the query fails.

Note: regular materialize_single_feature_view does not have this bug because it resolves join keys correctly through the provider layer.

Suggested Fix

         for source_fv in source_fvs:
-            all_join_keys.update(source_fv.entities)
+            all_join_keys.update(source_fv.join_keys)
             if source_fv.batch_source:
                 entity_timestamp_col_names.add(source_fv.batch_source.timestamp_field)

             job = provider.offline_store.pull_latest_from_table_or_query(
                 config=self.config,
                 data_source=source_fv.batch_source,
-                join_key_columns=source_fv.entities,
+                join_key_columns=source_fv.join_keys,
                 feature_name_columns=[f.name for f in source_fv.features],

Environment

• Feast version: 0.58.0
• Offline store: BigQuery

[anshishrivastava]

Hey, I'd like to fix this. It's a clear bug in _materialize_odfv where entity names are being used instead of join keys, causing BigQuery SQL to fail when they differ.

Proposed Solution:

1. Update sdk/python/feast/feature_store.py to use source_fv.join_keys on lines 1354 and 1394.
2. Add a unit test with an entity where name != join_key to prevent future regressions.

Mind assigning this to me? @franciscojavierarceo @ntkathole

[anshishrivastava]

PR for the fix - #6645