diff --git a/airflow/migrations/versions/0126_2_7_0_add_index_on_last_scheduling_decision_.py b/airflow/migrations/versions/0126_2_7_0_add_index_on_last_scheduling_decision_.py
new file mode 100644
index 0000000000000..6f94ce27dd137
--- /dev/null
+++ b/airflow/migrations/versions/0126_2_7_0_add_index_on_last_scheduling_decision_.py
@@ -0,0 +1,56 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+"""Add index on last_scheduling_decision NULLS FIRST, execution_date, state for queued dagrun
+
+Revision ID: 14db5484317e
+Revises: 937cbd173ca1
+Create Date: 2023-05-14 21:16:42.399167
+
+"""
+from __future__ import annotations
+
+from alembic import op
+from sqlalchemy import text
+
+# revision identifiers, used by Alembic.
+revision = "14db5484317e"
+down_revision = "937cbd173ca1"
+branch_labels = None
+depends_on = None
+airflow_version = "2.7.0"
+
+
+def upgrade():
+ """Apply Add index on last_scheduling_decision NULLS FIRST, execution_date, state for queued dagrun"""
+ conn = op.get_bind()
+ if conn.dialect.name == "postgresql":
+ with op.batch_alter_table("dag_run") as batch_op:
+ batch_op.create_index(
+ "idx_last_scheduling_decision_queued",
+ [text("last_scheduling_decision NULLS FIRST"), "execution_date", "state"],
+ postgresql_where=text("state='queued'"),
+ )
+
+
+def downgrade():
+ """Unapply Add index on last_scheduling_decision NULLS FIRST, execution_date, state for queued dagrun"""
+ conn = op.get_bind()
+ if conn.dialect.name == "postgresql":
+ with op.batch_alter_table("dag_run") as batch_op:
+ batch_op.drop_index("idx_last_scheduling_decision_queued")
diff --git a/airflow/models/dagrun.py b/airflow/models/dagrun.py
index 98810693cc1a1..be5c635ecc294 100644
--- a/airflow/models/dagrun.py
+++ b/airflow/models/dagrun.py
@@ -143,6 +143,15 @@ class DagRun(Base, LoggingMixin):
UniqueConstraint("dag_id", "execution_date", name="dag_run_dag_id_execution_date_key"),
UniqueConstraint("dag_id", "run_id", name="dag_run_dag_id_run_id_key"),
Index("idx_last_scheduling_decision", last_scheduling_decision),
+ Index(
+ "idx_last_scheduling_decision_queued",
+ # Not possible to add .nulls_first(), because only postgresql can handle Index like that.
+ # Migration script which contains postgres dialect check adds NULLS FIST to index.
+ last_scheduling_decision,
+ execution_date,
+ _state,
+ postgresql_where=text("state='queued'"),
+ ),
Index("idx_dag_run_dag_id", dag_id),
Index(
"idx_dag_run_running_dags",
diff --git a/docs/apache-airflow/img/airflow_erd.sha256 b/docs/apache-airflow/img/airflow_erd.sha256
index 1f2c2c1f3419a..8cde30d727163 100644
--- a/docs/apache-airflow/img/airflow_erd.sha256
+++ b/docs/apache-airflow/img/airflow_erd.sha256
@@ -1 +1 @@
-4987842fd67d29e194f1117e127d3291ba60d3fbc3e81cba75ce93884c263321
\ No newline at end of file
+811b1c45f8fa985feacacffafc30c82a6049bb33948c33bb218c13c48f971097
\ No newline at end of file
diff --git a/docs/apache-airflow/img/airflow_erd.svg b/docs/apache-airflow/img/airflow_erd.svg
index 8439c226f8b98..b531759ac4ec7 100644
--- a/docs/apache-airflow/img/airflow_erd.svg
+++ b/docs/apache-airflow/img/airflow_erd.svg
@@ -1225,7 +1225,7 @@
task_instance--xcom
-1
+0..N
1
@@ -1239,7 +1239,7 @@
task_instance--xcom
-0..N
+1
1
diff --git a/docs/apache-airflow/migrations-ref.rst b/docs/apache-airflow/migrations-ref.rst
index 2fdc682025a07..c29c0fbeb86bd 100644
--- a/docs/apache-airflow/migrations-ref.rst
+++ b/docs/apache-airflow/migrations-ref.rst
@@ -39,7 +39,10 @@ Here's the list of all the Database Migrations that are executed via when you ru
+---------------------------------+-------------------+-------------------+--------------------------------------------------------------+
| Revision ID | Revises ID | Airflow Version | Description |
+=================================+===================+===================+==============================================================+
-| ``937cbd173ca1`` (head) | ``98ae134e6fff`` | ``2.7.0`` | Add index to task_instance table |
+| ``14db5484317e`` (head) | ``937cbd173ca1`` | ``2.7.0`` | Add index on last_scheduling_decision NULLS FIRST, |
+| | | | execution_date, state for queued dagrun |
++---------------------------------+-------------------+-------------------+--------------------------------------------------------------+
+| ``937cbd173ca1`` | ``98ae134e6fff`` | ``2.7.0`` | Add index to task_instance table |
+---------------------------------+-------------------+-------------------+--------------------------------------------------------------+
| ``98ae134e6fff`` | ``6abdffdd4815`` | ``2.6.0`` | Increase length of user identifier columns in ``ab_user`` |
| | | | and ``ab_register_user`` tables |