[v3-1-test] Improve get dag grid structure endpoint speed (#55942) (#56937)

* [v3-1-test] Improve get dag grid structure endpoint speed (#55942)

* Improve get dag structure endpoint speed

---------
(cherry picked from commit 311277c)

Co-authored-by: dor-bernstein <[email protected]>
Co-authored-by: Elad Kalif <[email protected]>

* fixup! fixup! [v3-1-test] Improve get dag grid structure endpoint speed (#55942)

---------

Co-authored-by: dor-bernstein <[email protected]>
Co-authored-by: Elad Kalif <[email protected]>

Author: 3 people

airflow-core/src/airflow/api_fastapi/core_api/routes/ui/grid.py

@@ -161,6 +161,9 @@ def get_dag_structure(
 
     serdags = session.scalars(
         select(SerializedDagModel).where(
+            # Even though dag_id is filtered in base_query,
+            # adding this line here can improve the performance of this endpoint
+            SerializedDagModel.dag_id == dag_id,
             SerializedDagModel.id != latest_serdag.id,
             SerializedDagModel.dag_version_id.in_(
                 select(TaskInstance.dag_version_id)