Narrow eager-load options on hot SQL/data read paths

datajunction-server/datajunction_server/api/data.py

@@ -25,6 +25,7 @@
 )
 from datajunction_server.construction.build_v3.types import GeneratedSQL
 from datajunction_server.database.availabilitystate import AvailabilityState
+from datajunction_server.database.catalog import Catalog
 from datajunction_server.database.history import History
 from datajunction_server.database.node import Node, NodeRevision
 from datajunction_server.database.user import User
@@ -364,7 +365,16 @@ async def get_data(
 
     node = cast(
         Node,
-        await Node.get_by_name(session, node_name, raise_if_not_exists=True),
+        await Node.get_by_name(
+            session,
+            node_name,
+            options=[
+                joinedload(Node.current).options(
+                    joinedload(NodeRevision.catalog).joinedload(Catalog.engines),
+                ),
+            ],
+            raise_if_not_exists=True,
+        ),
     )
     engine = await resolve_engine(
         session=session,
@@ -418,7 +428,16 @@ async def get_data_stream_for_node(
     request_headers = dict(request.headers)
     node = cast(
         Node,
-        await Node.get_by_name(session, node_name, raise_if_not_exists=True),
+        await Node.get_by_name(
+            session,
+            node_name,
+            options=[
+                joinedload(Node.current).options(
+                    joinedload(NodeRevision.catalog).joinedload(Catalog.engines),
+                ),
+            ],
+            raise_if_not_exists=True,
+        ),
     )
     engine = await resolve_engine(
         session=session,

datajunction-server/datajunction_server/api/metrics.py

@@ -7,7 +7,7 @@
 from fastapi import BackgroundTasks, Depends, HTTPException, Query
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy.orm import selectinload
+from sqlalchemy.orm import load_only, noload, selectinload
 from sqlalchemy.sql.operators import is_
 
 from datajunction_server.api.nodes import list_nodes
@@ -130,6 +130,11 @@ async def get_common_dimensions(
     input_errors = []
     statement = (
         select(Node)
+        .options(
+            load_only(Node.id, Node.name, Node.type, Node.current_version),
+            noload(Node.created_by),
+            noload(Node.tags),
+        )
         .where(Node.name.in_(metric))  # type: ignore
         .where(is_(Node.deactivated_at, None))
     )

datajunction-server/datajunction_server/api/sql.py

@@ -9,6 +9,7 @@
 from typing import cast
 
 from fastapi import BackgroundTasks, Depends, Query, Request
+from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from datajunction_server.construction.build_v3 import (
@@ -702,11 +703,17 @@ async def get_sql_for_metrics(
     # Label this session for debugging
     session.info["session_label"] = "initial node loading"
 
-    # Fetch all metric nodes in a single query (only name/type needed for validation here)
-    nodes = await Node.get_by_names(session, metrics, options=[])
+    # Fetch only name/type for validation here — no need to hydrate full
+    # Node entities (which would trigger the mapper-level created_by/tags
+    # selectin loads on each row).
+    node_rows = (
+        await session.execute(
+            select(Node.name, Node.type).where(Node.name.in_(metrics)),
+        )
+    ).all()
 
     # Check if all requested nodes exist
-    found_names = {node.name for node in nodes}
+    found_names = {row.name for row in node_rows}
     missing_nodes = set(metrics) - found_names
     if missing_nodes:
         raise DJInvalidInputException(
@@ -715,11 +722,11 @@ async def get_sql_for_metrics(
         )
 
     # Validate node types
-    non_metric_nodes = [node for node in nodes if node and node.type != NodeType.METRIC]
+    non_metric_nodes = [row for row in node_rows if row.type != NodeType.METRIC]
     if non_metric_nodes:
         raise DJInvalidInputException(
             message="All nodes must be of metric type, but some are not: "
-            f"{', '.join([f'{n.name} ({n.type})' for n in non_metric_nodes])} .",
+            f"{', '.join([f'{row.name} ({row.type})' for row in non_metric_nodes])} .",
             http_status_code=HTTPStatus.UNPROCESSABLE_ENTITY,
         )
 

datajunction-server/datajunction_server/internal/sql.py

@@ -136,7 +136,16 @@ async def build_node_sql(
 
     node = cast(
         Node,
-        await Node.get_by_name(session, node_name, raise_if_not_exists=True),
+        await Node.get_by_name(
+            session,
+            node_name,
+            options=[
+                joinedload(Node.current).options(
+                    joinedload(NodeRevision.catalog).joinedload(Catalog.engines),
+                ),
+            ],
+            raise_if_not_exists=True,
+        ),
     )
     if not engine:  # pragma: no cover
         engine = node.current.catalog.engines[0]