Add an option to include dimension records into general query result …

…(DM-47980)

The `GeneralQueryResults.iter_tuples` method returned DataIds without
dimension records. In some cases (e.g. for obscore export) it would be
very useful to include records in the same result to avoid querying
them separately. New method `with_dimension_records` is added to the class
to trigger adding fields from all dimension records into returned page.
This will produce many duplicates for some dimensions (e.g. `instrument`)
but it keeps page structure simple.

This adds one attribute to the `GeneralResultSpec` class, will need some
care with Butler server compatibility.

python/lsst/daf/butler/direct_query_driver/_result_page_converter.py

@@ -326,17 +326,35 @@ class GeneralResultPageConverter(ResultPageConverter):  # numpydoc ignore=PR01
 
     def __init__(self, spec: GeneralResultSpec, ctx: ResultPageConverterContext) -> None:
         self.spec = spec
-
-        result_columns = spec.get_result_columns()
+        # In case `spec.include_dimension_records` is True then in addition to
+        # columns returned by the query we have to add columns from dimension
+        # records that are not returned by the query. These columns belong to
+        # either cached or skypix dimensions.
+        query_result_columns = set(spec.get_result_columns())
+        output_columns = spec.get_all_result_columns()
+        universe = spec.dimensions.universe
         self.converters: list[_GeneralColumnConverter] = []
-        for column in result_columns:
+        for column in output_columns:
             column_name = qt.ColumnSet.get_qualified_name(column.logical_table, column.field)
-            if column.field == TimespanDatabaseRepresentation.NAME:
-                self.converters.append(_TimespanGeneralColumnConverter(column_name, ctx.db))
+            converter: _GeneralColumnConverter
+            if column not in query_result_columns and column.field is not None:
+                # This must be a field from a cached dimension record or
+                # skypix record.
+                assert isinstance(column.logical_table, str), "Do not expect AnyDatasetType here"
+                element = universe[column.logical_table]
+                if isinstance(element, SkyPixDimension):
+                    converter = _SkypixRecordGeneralColumnConverter(element, column.field)
+                else:
+                    converter = _CachedRecordGeneralColumnConverter(
+                        element, column.field, ctx.dimension_record_cache
+                    )
+            elif column.field == TimespanDatabaseRepresentation.NAME:
+                converter = _TimespanGeneralColumnConverter(column_name, ctx.db)
             elif column.field == "ingest_date":
-                self.converters.append(_TimestampGeneralColumnConverter(column_name))
+                converter = _TimestampGeneralColumnConverter(column_name)
             else:
-                self.converters.append(_DefaultGeneralColumnConverter(column_name))
+                converter = _DefaultGeneralColumnConverter(column_name)
+            self.converters.append(converter)
 
     def convert(self, raw_rows: Iterable[sqlalchemy.Row]) -> GeneralResultPage:
         rows = [tuple(cvt.convert(row) for cvt in self.converters) for row in raw_rows]
@@ -422,3 +440,47 @@ def __init__(self, name: str, db: Database):
     def convert(self, row: sqlalchemy.Row) -> Any:
         timespan = self.timespan_class.extract(row._mapping, self.name)
         return timespan
+
+
+class _CachedRecordGeneralColumnConverter(_GeneralColumnConverter):
+    """Helper for converting result row into a field value for cached
+    dimension records.
+
+    Parameters
+    ----------
+    element : `DimensionElement`
+        Dimension element, must be of cached type.
+    field : `str`
+        Name of the field to extract from the dimension record.
+    cache : `DimensionRecordCache`
+        Cache for dimension records.
+    """
+
+    def __init__(self, element: DimensionElement, field: str, cache: DimensionRecordCache) -> None:
+        self._record_converter = _CachedDimensionRecordRowConverter(element, cache)
+        self._field = field
+
+    def convert(self, row: sqlalchemy.Row) -> Any:
+        record = self._record_converter.convert(row)
+        return getattr(record, self._field)
+
+
+class _SkypixRecordGeneralColumnConverter(_GeneralColumnConverter):
+    """Helper for converting result row into a field value for skypix
+    dimension records.
+
+    Parameters
+    ----------
+    element : `SkyPixDimension`
+        Dimension element.
+    field : `str`
+        Name of the field to extract from the dimension record.
+    """
+
+    def __init__(self, element: SkyPixDimension, field: str) -> None:
+        self._record_converter = _SkypixDimensionRecordRowConverter(element)
+        self._field = field
+
+    def convert(self, row: sqlalchemy.Row) -> Any:
+        record = self._record_converter.convert(row)
+        return getattr(record, self._field)

python/lsst/daf/butler/queries/_general_query_results.py

@@ -35,11 +35,11 @@
 
 from .._dataset_ref import DatasetRef
 from .._dataset_type import DatasetType
-from ..dimensions import DataCoordinate, DimensionGroup
+from ..dimensions import DataCoordinate, DimensionElement, DimensionGroup, DimensionRecord
 from ._base import QueryResultsBase
 from .driver import QueryDriver
 from .result_specs import GeneralResultSpec
-from .tree import QueryTree
+from .tree import QueryTree, ResultColumn
 
 
 class GeneralResultTuple(NamedTuple):
@@ -99,9 +99,20 @@ def __iter__(self) -> Iterator[dict[str, Any]]:
             fields (separated from dataset type name by dot).
         """
         for page in self._driver.execute(self._spec, self._tree):
-            columns = tuple(str(column) for column in page.spec.get_result_columns())
+            columns = tuple(str(column) for column in page.spec.get_all_result_columns())
             for row in page.rows:
-                yield dict(zip(columns, row))
+                try:
+                    yield dict(zip(columns, row, strict=True))
+                except ValueError:
+                    message = (
+                        "Inconsistent size of columns and data rows in general result -- "
+                        f"columns: {columns}, row: {row}"
+                    )
+                    if len(columns) > len(row):
+                        # Probably means that server does not know about
+                        # `include_dimension_records` in the spec.
+                        message += " (may mean that Butler server needs an upgrade)"
+                    raise ValueError(message) from None
 
     def iter_tuples(self, *dataset_types: DatasetType) -> Iterator[GeneralResultTuple]:
         """Iterate over result rows and return data coordinate, and dataset
@@ -125,14 +136,10 @@ def iter_tuples(self, *dataset_types: DatasetType) -> Iterator[GeneralResultTupl
             run_key = f"{dataset_type.name}.run"
             dataset_keys.append((dataset_type, dimensions, id_key, run_key))
         for row in self:
-            values = tuple(
-                row[key] for key in itertools.chain(all_dimensions.required, all_dimensions.implied)
-            )
-            data_coordinate = DataCoordinate.from_full_values(all_dimensions, values)
+            data_coordinate = self._make_data_id(row, all_dimensions)
             refs = []
             for dataset_type, dimensions, id_key, run_key in dataset_keys:
-                values = tuple(row[key] for key in itertools.chain(dimensions.required, dimensions.implied))
-                data_id = DataCoordinate.from_full_values(dimensions, values)
+                data_id = self._make_data_id(row, dimensions)
                 refs.append(DatasetRef(dataset_type, data_id, row[run_key], id=row[id_key]))
             yield GeneralResultTuple(data_id=data_coordinate, refs=refs, raw_row=row)
 
@@ -141,6 +148,19 @@ def dimensions(self) -> DimensionGroup:
         # Docstring inherited
         return self._spec.dimensions
 
+    @property
+    def has_dimension_records(self) -> bool:
+        """Whether all data IDs in this iterable contain dimension records."""
+        return self._spec.include_dimension_records
+
+    def with_dimension_records(self) -> GeneralQueryResults:
+        """Return a results object for which `has_dimension_records` is
+        `True`.
+        """
+        if self.has_dimension_records:
+            return self
+        return self._copy(tree=self._tree, include_dimension_records=True)
+
     def count(self, *, exact: bool = True, discard: bool = False) -> int:
         # Docstring inherited.
         return self._driver.count(self._tree, self._spec, exact=exact, discard=discard)
@@ -152,3 +172,27 @@ def _copy(self, tree: QueryTree, **kwargs: Any) -> GeneralQueryResults:
     def _get_datasets(self) -> frozenset[str]:
         # Docstring inherited.
         return frozenset(self._spec.dataset_fields)
+
+    def _make_data_id(self, row: dict[str, Any], dimensions: DimensionGroup) -> DataCoordinate:
+        values = tuple(row[key] for key in itertools.chain(dimensions.required, dimensions.implied))
+        data_coordinate = DataCoordinate.from_full_values(dimensions, values)
+        if self.has_dimension_records:
+            records = {
+                name: self._make_dimension_record(row, dimensions.universe[name])
+                for name in dimensions.elements
+            }
+            data_coordinate = data_coordinate.expanded(records)
+        return data_coordinate
+
+    def _make_dimension_record(self, row: dict[str, Any], element: DimensionElement) -> DimensionRecord:
+        column_map = list(
+            zip(
+                element.schema.dimensions.names,
+                element.dimensions.names,
+            )
+        )
+        for field in element.schema.remainder.names:
+            column_map.append((field, str(ResultColumn(element.name, field))))
+        d = {k: row[v] for k, v in column_map}
+        record_cls = element.RecordClass
+        return record_cls(**d)

python/lsst/daf/butler/queries/result_specs.py

@@ -213,6 +213,11 @@ class GeneralResultSpec(ResultSpecBase):
     dataset_fields: Mapping[str, set[DatasetFieldName]]
     """Dataset fields included in this query."""
 
+    include_dimension_records: bool = False
+    """Whether to include fields for all dimension records, in addition to
+    explicitly specified in `dimension_fields`.
+    """
+
     find_first: bool
     """Whether this query requires find-first resolution for a dataset.
 
@@ -241,6 +246,33 @@ def get_result_columns(self) -> ColumnSet:
             result.dimension_fields[element_name].update(fields_for_element)
         for dataset_type, fields_for_dataset in self.dataset_fields.items():
             result.dataset_fields[dataset_type].update(fields_for_dataset)
+        if self.include_dimension_records:
+            # This only adds record fields for non-cached and non-skypix
+            # elements, this is what we want when generating query. We could
+            # potentially add those too but it may make queries slower, so
+            # instead we query cached dimension records separately and add them
+            # to the result page in the page converter.
+            _add_dimension_records_to_column_set(self.dimensions, result)
+        return result
+
+    def get_all_result_columns(self) -> ColumnSet:
+        """Return all columns that have to appear in the result. This includes
+        columns for all dimension records for all dimensions if
+        ``include_dimension_records`` is `True`.
+
+        Returns
+        -------
+        columns : `ColumnSet`
+            Full column set.
+        """
+        dimensions = self.dimensions
+        result = self.get_result_columns()
+        if self.include_dimension_records:
+            for element_name in dimensions.elements:
+                element = dimensions.universe[element_name]
+                # Non-cached dimensions are already there, but it does not harm
+                # to add them again.
+                result.dimension_fields[element_name].update(element.schema.remainder.names)
         return result
 
     @pydantic.model_validator(mode="after")

python/lsst/daf/butler/remote_butler/_query_driver.py

@@ -257,7 +257,7 @@ def _convert_query_result_page(
 
 def _convert_general_result(spec: GeneralResultSpec, model: GeneralResultModel) -> GeneralResultPage:
     """Convert GeneralResultModel to a general result page."""
-    columns = spec.get_result_columns()
+    columns = spec.get_all_result_columns()
     serializers = [
         columns.get_column_spec(column.logical_table, column.field).serializer() for column in columns
     ]

python/lsst/daf/butler/remote_butler/server/handlers/_query_serialization.py

@@ -79,7 +79,7 @@ def convert_query_page(spec: ResultSpec, page: ResultPage) -> QueryExecuteResult
 
 def _convert_general_result(page: GeneralResultPage) -> GeneralResultModel:
     """Convert GeneralResultPage to a serializable model."""
-    columns = page.spec.get_result_columns()
+    columns = page.spec.get_all_result_columns()
     serializers = [
         columns.get_column_spec(column.logical_table, column.field).serializer() for column in columns
     ]

python/lsst/daf/butler/tests/butler_queries.py

@@ -436,7 +436,9 @@ def test_general_query(self) -> None:
                 self.assertEqual(len(row_tuple.refs), 1)
                 self.assertEqual(row_tuple.refs[0].datasetType, flat)
                 self.assertTrue(row_tuple.refs[0].dataId.hasFull())
+                self.assertFalse(row_tuple.refs[0].dataId.hasRecords())
                 self.assertTrue(row_tuple.data_id.hasFull())
+                self.assertFalse(row_tuple.data_id.hasRecords())
                 self.assertEqual(row_tuple.data_id.dimensions, dimensions)
                 self.assertEqual(row_tuple.raw_row["flat.run"], "imported_g")
 
@@ -511,6 +513,46 @@ def test_general_query(self) -> None:
                 {Timespan(t1, t2), Timespan(t2, t3), Timespan(t3, None), Timespan.makeEmpty(), None},
             )
 
+        dimensions = butler.dimensions["detector"].minimal_group
+
+        # Include dimension records into query.
+        with butler.query() as query:
+            query = query.join_dimensions(dimensions)
+            result = query.general(dimensions).order_by("detector")
+            rows = list(result.with_dimension_records())
+            self.assertEqual(
+                rows[0],
+                {
+                    "instrument": "Cam1",
+                    "detector": 1,
+                    "instrument.visit_max": 1024,
+                    "instrument.visit_system": 1,
+                    "instrument.exposure_max": 512,
+                    "instrument.detector_max": 4,
+                    "instrument.class_name": "lsst.pipe.base.Instrument",
+                    "detector.full_name": "Aa",
+                    "detector.name_in_raft": "a",
+                    "detector.raft": "A",
+                    "detector.purpose": "SCIENCE",
+                },
+            )
+
+        dimensions = butler.dimensions.conform(["detector", "physical_filter"])
+
+        # DataIds should come with records.
+        with butler.query() as query:
+            query = query.join_dataset_search("flat", "imported_g")
+            result = query.general(dimensions, dataset_fields={"flat": ...}, find_first=True).order_by(
+                "detector"
+            )
+            result = result.with_dimension_records()
+            row_tuples = list(result.iter_tuples(flat))
+            self.assertEqual(len(row_tuples), 3)
+            for row_tuple in row_tuples:
+                self.assertTrue(row_tuple.data_id.hasRecords())
+                self.assertEqual(len(row_tuple.refs), 1)
+                self.assertTrue(row_tuple.refs[0].dataId.hasRecords())
+
     def test_query_ingest_date(self) -> None:
         """Test general query returning ingest_date field."""
         before_ingest = astropy.time.Time.now()