Remove datastore records from serialized DatasetRef (DM-41226)

This removes the piece of code for (de-)serializing datastore records in
DatasetRef that was added on DM-40053. We worry that serialized QuantumGraph
could grow in size, though presently we do not fill datastore records when
we make refs for quantum graph. In the future the whole thing will be
replaced by a more efficient data structures, so this serialization will
likely disappear entirely.

python/lsst/daf/butler/_dataset_ref.py

@@ -182,10 +182,6 @@ def makeDatasetId(
 # This is constant, so don't recreate a set for each instance
 _serializedDatasetRefFieldsSet = {"id", "datasetType", "dataId", "run", "component"}
 
-# Serialized representation of StoredDatastoreItemInfo collection, first item
-# is the record class name.
-_DatastoreRecords: TypeAlias = tuple[str, list[Mapping[str, Any]]]
-
 
 class SerializedDatasetRef(_BaseModelCompat):
     """Simplified model of a `DatasetRef` suitable for serialization."""
@@ -195,8 +191,6 @@ class SerializedDatasetRef(_BaseModelCompat):
     dataId: SerializedDataCoordinate | None = None
     run: StrictStr | None = None
     component: StrictStr | None = None
-    datastore_records: Mapping[str, _DatastoreRecords] | None = None
-    """Maps opaque table name to datastore records."""
 
     if PYDANTIC_V2:
         # Can not use "after" validator since in some cases the validator
@@ -237,7 +231,6 @@ def direct(
         datasetType: dict[str, Any] | None = None,
         dataId: dict[str, Any] | None = None,
         component: str | None = None,
-        datastore_records: Mapping[str, _DatastoreRecords] | None = None,
     ) -> SerializedDatasetRef:
         """Construct a `SerializedDatasetRef` directly without validators.
 
@@ -264,7 +257,6 @@ def direct(
             dataId=serialized_dataId,
             run=sys.intern(run),
             component=component,
-            datastore_records=datastore_records,
         )
 
         return node
@@ -430,19 +422,11 @@ def to_simple(self, minimal: bool = False) -> SerializedDatasetRef:
                 simple["component"] = self.datasetType.component()
             return SerializedDatasetRef(**simple)
 
-        datastore_records: Mapping[str, _DatastoreRecords] | None = None
-        if self._datastore_records is not None:
-            datastore_records = {}
-            for opaque_name, records in self._datastore_records.items():
-                class_name, record_dicts = StoredDatastoreItemInfo.to_records(records)
-                datastore_records[opaque_name] = class_name, list(record_dicts)
-
         return SerializedDatasetRef(
             datasetType=self.datasetType.to_simple(minimal=minimal),
             dataId=self.dataId.to_simple(),
             run=self.run,
             id=self.id,
-            datastore_records=datastore_records,
         )
 
     @classmethod
@@ -537,20 +521,11 @@ def from_simple(
                 f"Encountered with {simple!r}{dstr}."
             )
 
-        # rebuild datastore records
-        datastore_records: DatasetDatastoreRecords | None = None
-        if simple.datastore_records is not None:
-            datastore_records = {}
-            for opaque_name, (class_name, records) in simple.datastore_records.items():
-                infos = StoredDatastoreItemInfo.from_records(class_name, records)
-                datastore_records[opaque_name] = infos
-
         newRef = cls(
             datasetType,
             dataId,
             id=simple.id,
             run=simple.run,
-            datastore_records=datastore_records,
         )
         if cache is not None:
             cache[key] = newRef

tests/test_datasets.py

@@ -709,13 +709,13 @@ def testJson(self) -> None:
         s = ref.to_json()
         self.assertEqual(DatasetRef.from_json(s, universe=self.universe), ref)
 
-        # Also test ref with datastore records
+        # Also test ref with datastore records, serialization does not
+        # preserve those.
         ref = self._make_datastore_records(ref, "/path1", "/path2")
         s = ref.to_json()
         ref2 = DatasetRef.from_json(s, universe=self.universe)
         self.assertEqual(ref2, ref)
-        self.assertIsNotNone(ref2._datastore_records)
-        self.assertEqual(ref2._datastore_records, ref._datastore_records)
+        self.assertIsNone(ref2._datastore_records)
 
     def testFileDataset(self) -> None:
         ref = DatasetRef(self.datasetType, self.dataId, run="somerun")