From 3ca67f46a4ef9c4711395ce80a085f54ceabf517 Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Tue, 19 Aug 2025 20:14:50 +0500
Subject: [PATCH 01/12] WIP: added migration file.

---
 .../timed_beliefs_materialized_views.py       | 63 +++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py

diff --git a/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py b/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py
new file mode 100644
index 0000000000..f4aa64e4d5
--- /dev/null
+++ b/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py
@@ -0,0 +1,63 @@
+"""Add materialized view for belief optimization
+
+Revision ID: c98798csds8c
+Revises: b8f3cda5e023
+Create Date: 2025-08-08 04:55:33.722545
+
+"""
+
+from alembic import op
+
+# revision identifiers
+revision = "c98798csds8c"
+down_revision = "b8f3cda5e023"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Create the materialized view with proper alias
+    op.execute(
+        """
+        CREATE MATERIALIZED VIEW timed_belief_min_v AS
+        SELECT *
+        FROM (
+            SELECT
+                timed_belief.sensor_id,
+                timed_belief.event_start,
+                timed_belief.source_id,
+                MIN(timed_belief.belief_horizon) AS most_recent_belief_horizon
+            FROM timed_belief
+            INNER JOIN data_source
+                ON data_source.id = timed_belief.source_id
+            GROUP BY
+                timed_belief.sensor_id,
+                timed_belief.event_start,
+                timed_belief.source_id
+        ) AS belief_mins
+        GROUP BY
+            sensor_id,
+            event_start,
+            source_id,
+            most_recent_belief_horizon;
+    """
+    )
+
+    # Create indexes
+    op.execute(
+        """
+        CREATE INDEX idx_timed_belief_min_v_sensor_event
+        ON timed_belief_min_v(sensor_id, event_start);
+    """
+    )
+
+    op.execute(
+        """
+        CREATE INDEX idx_timed_belief_min_v_event_start
+        ON timed_belief_min_v(event_start);
+    """
+    )
+
+
+def downgrade():
+    op.execute("DROP MATERIALIZED VIEW IF EXISTS timed_belief_min_v CASCADE;")

From 14226badb047b117dbc8c3bb86de37c258fd0250 Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Wed, 20 Aug 2025 19:23:11 +0500
Subject: [PATCH 02/12] Added materialized view boolean to backend logic and
 created CLI command for refresh.

---
 flexmeasures/api/dev/sensors.py               |  5 +++
 flexmeasures/api/v3_0/assets.py               |  5 +++
 flexmeasures/cli/db_ops.py                    | 29 +++++++++++++++
 flexmeasures/data/models/generic_assets.py    |  6 +++-
 flexmeasures/data/models/time_series.py       | 10 +++++-
 .../data/schemas/tests/test_input_schema.py   |  2 ++
 flexmeasures/utils/validation_utils.py        | 35 +++++++++++++++++++
 7 files changed, 90 insertions(+), 2 deletions(-)

diff --git a/flexmeasures/api/dev/sensors.py b/flexmeasures/api/dev/sensors.py
index b8f52669e0..9a5dbadfc9 100644
--- a/flexmeasures/api/dev/sensors.py
+++ b/flexmeasures/api/dev/sensors.py
@@ -20,6 +20,9 @@
 from flexmeasures.data.models.time_series import Sensor
 from flexmeasures.data.services.annotations import prepare_annotations_for_chart
 from flexmeasures.ui.utils.view_utils import set_session_variables
+from flexmeasures.utils.validation_utils import (
+    validate_timed_belief_min_v,
+)
 
 
 class SensorAPI(FlaskView):
@@ -90,6 +93,7 @@ def get_chart(self, id: int, sensor: Sensor, **kwargs):
             "most_recent_beliefs_only": fields.Boolean(
                 required=False, load_default=True
             ),
+            "use_materialized_view": fields.Boolean(required=False, load_default=True),
         },
         location="query",
     )
@@ -110,6 +114,7 @@ def get_chart_data(self, id: int, sensor: Sensor, **kwargs):
         - "resolution" (see :ref:`resolutions`)
         - "most_recent_beliefs_only" (if true, returns the most recent belief for each event; if false, returns each belief for each event; defaults to true)
         """
+        kwargs["timed_belief_min_v"] = validate_timed_belief_min_v(db.session)
         return sensor.search_beliefs(as_json=True, **kwargs)
 
     @route("/<id>/chart_annotations", strict_slashes=False)
diff --git a/flexmeasures/api/v3_0/assets.py b/flexmeasures/api/v3_0/assets.py
index 55a13a8e24..4b123e298a 100644
--- a/flexmeasures/api/v3_0/assets.py
+++ b/flexmeasures/api/v3_0/assets.py
@@ -47,6 +47,9 @@
 from flexmeasures.utils.coding_utils import (
     flatten_unique,
 )
+from flexmeasures.utils.validation_utils import (
+    validate_timed_belief_min_v,
+)
 from flexmeasures.ui.utils.view_utils import clear_session, set_session_variables
 from flexmeasures.auth.policy import check_access
 from werkzeug.exceptions import Forbidden, Unauthorized
@@ -657,6 +660,7 @@ def get_chart(self, id: int, asset: GenericAsset, **kwargs):
             "beliefs_after": AwareDateTimeField(format="iso", required=False),
             "beliefs_before": AwareDateTimeField(format="iso", required=False),
             "most_recent_beliefs_only": fields.Boolean(required=False),
+            "use_materialized_view": fields.Boolean(required=False, load_default=True),
         },
         location="query",
     )
@@ -669,6 +673,7 @@ def get_chart_data(self, id: int, asset: GenericAsset, **kwargs):
         Data for use in charts (in case you have the chart specs already).
         """
         sensors = flatten_unique(asset.validate_sensors_to_show())
+        kwargs["timed_belief_min_v"] = validate_timed_belief_min_v(db.session)
         return asset.search_beliefs(sensors=sensors, as_json=True, **kwargs)
 
     @route("/<id>/auditlog")
diff --git a/flexmeasures/cli/db_ops.py b/flexmeasures/cli/db_ops.py
index 21173150ef..01c04a41cf 100644
--- a/flexmeasures/cli/db_ops.py
+++ b/flexmeasures/cli/db_ops.py
@@ -9,6 +9,7 @@
 import click
 
 from flexmeasures.cli.utils import MsgStyle
+from flexmeasures.data import db
 
 
 @click.group("db-ops")
@@ -95,4 +96,32 @@ def restore(file: str):
         click.secho("db restore unsuccessful", **MsgStyle.ERROR)
 
 
+@fm_db_ops.command("refresh-materialized-views")
+@with_appcontext
+@click.option("--concurrent", is_flag=True, default=False)
+def refresh_materialized_views(concurrent: bool):
+    """Refresh materialized views for better query performance."""
+    from sqlalchemy import text
+
+    refresh_type = "CONCURRENTLY" if concurrent else ""
+    import time
+
+    start_time = time.time()
+    click.echo(
+        f"Refreshing materialized views {'CONCURRENTLY' if concurrent else 'without concurrency'}..."
+    )
+    try:
+        db.session.execute(
+            text(f"REFRESH MATERIALIZED {refresh_type} VIEW timed_belief_min_v;")
+        )
+        db.session.commit()
+        elapsed_time = time.time() - start_time
+        click.echo(
+            f"✓ Materialized views refreshed successfully in {elapsed_time:.2f} seconds"
+        )
+    except Exception as e:
+        db.session.rollback()
+        click.echo(f"✗ Error refreshing materialized views: {e}")
+
+
 app.cli.add_command(fm_db_ops)
diff --git a/flexmeasures/data/models/generic_assets.py b/flexmeasures/data/models/generic_assets.py
index 4aae30d47f..564dbc312c 100644
--- a/flexmeasures/data/models/generic_assets.py
+++ b/flexmeasures/data/models/generic_assets.py
@@ -7,7 +7,7 @@
 from flask import current_app
 from flask_security import current_user
 import pandas as pd
-from sqlalchemy import select
+from sqlalchemy import select, Table
 from sqlalchemy.engine import Row
 from sqlalchemy.ext.hybrid import hybrid_method
 from sqlalchemy.sql.expression import func, text
@@ -647,6 +647,8 @@ def search_beliefs(
         most_recent_events_only: bool = False,
         as_json: bool = False,
         resolution: timedelta | None = None,
+        use_materialized_view: bool = True,
+        timed_belief_min_v: Table | None = None,
     ) -> BeliefsDataFrame | str:
         """Search all beliefs about events for all sensors of this asset
 
@@ -686,6 +688,8 @@ def search_beliefs(
                 most_recent_events_only=most_recent_events_only,
                 one_deterministic_belief_per_event_per_source=True,
                 resolution=resolution,
+                use_materialized_view=use_materialized_view,
+                timed_belief_min_v=timed_belief_min_v,
             )
         if as_json:
             from flexmeasures.data.services.time_series import simplify_index
diff --git a/flexmeasures/data/models/time_series.py b/flexmeasures/data/models/time_series.py
index 803a541053..2b068c57c4 100644
--- a/flexmeasures/data/models/time_series.py
+++ b/flexmeasures/data/models/time_series.py
@@ -8,7 +8,7 @@
 from flask import current_app
 
 import pandas as pd
-from sqlalchemy import select
+from sqlalchemy import select, Table
 from sqlalchemy.ext.declarative import declared_attr
 from sqlalchemy.ext.mutable import MutableDict
 from sqlalchemy.schema import UniqueConstraint
@@ -354,6 +354,8 @@ def search_beliefs(
         one_deterministic_belief_per_event_per_source: bool = False,
         as_json: bool = False,
         resolution: str | timedelta | None = None,
+        use_materialized_view: bool = True,
+        timed_belief_min_v: Table | None = None,
     ) -> tb.BeliefsDataFrame | str:
         """Search all beliefs about events for this sensor.
 
@@ -398,6 +400,8 @@ def search_beliefs(
             one_deterministic_belief_per_event=one_deterministic_belief_per_event,
             one_deterministic_belief_per_event_per_source=one_deterministic_belief_per_event_per_source,
             resolution=resolution,
+            use_materialized_view=use_materialized_view,
+            timed_belief_min_v=timed_belief_min_v,
         )
         if as_json:
             df = bdf.reset_index()
@@ -715,6 +719,8 @@ def search(
         one_deterministic_belief_per_event_per_source: bool = False,
         resolution: str | timedelta = None,
         sum_multiple: bool = True,
+        use_materialized_view: bool = True,
+        timed_belief_min_v: Table | None = None,
     ) -> tb.BeliefsDataFrame | dict[str, tb.BeliefsDataFrame]:
         """Search all beliefs about events for the given sensors.
 
@@ -798,6 +804,8 @@ def search(
                 **most_recent_filters,
                 custom_filter_criteria=source_criteria,
                 custom_join_targets=custom_join_targets,
+                use_materialized_view=use_materialized_view,
+                timed_belief_min_v=timed_belief_min_v,
             )
             if use_latest_version_per_event:
                 bdf = keep_latest_version(
diff --git a/flexmeasures/data/schemas/tests/test_input_schema.py b/flexmeasures/data/schemas/tests/test_input_schema.py
index 37fd6daf10..325c395332 100644
--- a/flexmeasures/data/schemas/tests/test_input_schema.py
+++ b/flexmeasures/data/schemas/tests/test_input_schema.py
@@ -18,6 +18,8 @@ def test_input_schema():
     # These arguments are not mapped to a field at all (state a reason)
     excluded_arg_names = [
         "as_json",  # used in Sensor.search_beliefs but not in TimedBelief.search
+        "timed_belief_min_v",  # used in Sensor.search_beliefs but not in TimedBelief.search
+        "use_materialized_view",  # used in Sensor.search_beliefs but not in
     ]
 
     arg_names_without_associated_fields = [
diff --git a/flexmeasures/utils/validation_utils.py b/flexmeasures/utils/validation_utils.py
index 50935ed544..183d967feb 100644
--- a/flexmeasures/utils/validation_utils.py
+++ b/flexmeasures/utils/validation_utils.py
@@ -1,4 +1,6 @@
 import re
+from sqlalchemy import MetaData, Table, Column, Integer, DateTime, Interval
+from sqlalchemy.sql import text
 
 
 def validate_color_hex(value):
@@ -51,3 +53,36 @@ def validate_url(value):
         )
 
     return value
+
+
+def validate_timed_belief_min_v(session) -> Table | None:
+    """Define the structure of the timed_belief_min_v materialized view if it exists."""
+    # Check if materialized view exists
+    result = session.execute(
+        text(
+            """
+            SELECT EXISTS (
+                SELECT FROM information_schema.tables
+                WHERE table_name = 'timed_belief_min_v'
+                AND table_schema = 'public'
+            );
+        """
+        )
+    )
+
+    exists = result.scalar()
+    if not exists:
+        return None
+    print("Using timed_belief_min_v materialized view for optimized queries.")
+
+    # Only create the table definition if it exists
+    metadata = MetaData()
+    timed_belief_min_v = Table(
+        "timed_belief_min_v",
+        metadata,
+        Column("sensor_id", Integer),
+        Column("event_start", DateTime),
+        Column("source_id", Integer),
+        Column("most_recent_belief_horizon", Interval),
+    )
+    return timed_belief_min_v

From ce19cb012bd0a3e08969016e989aab74f118c7ec Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Fri, 22 Aug 2025 20:08:26 +0500
Subject: [PATCH 03/12] Added refresh interval, Fixed some bugs.

---
 flexmeasures/api/dev/sensors.py        |  4 +-
 flexmeasures/api/v3_0/assets.py        |  4 +-
 flexmeasures/ui/templates/base.html    | 96 +++++++++++++++++++++++++-
 flexmeasures/ui/views/assets/views.py  |  4 ++
 flexmeasures/utils/config_defaults.py  |  1 +
 flexmeasures/utils/validation_utils.py | 22 +-----
 6 files changed, 105 insertions(+), 26 deletions(-)

diff --git a/flexmeasures/api/dev/sensors.py b/flexmeasures/api/dev/sensors.py
index 9a5dbadfc9..ec54f821f3 100644
--- a/flexmeasures/api/dev/sensors.py
+++ b/flexmeasures/api/dev/sensors.py
@@ -21,7 +21,7 @@
 from flexmeasures.data.services.annotations import prepare_annotations_for_chart
 from flexmeasures.ui.utils.view_utils import set_session_variables
 from flexmeasures.utils.validation_utils import (
-    validate_timed_belief_min_v,
+    get_timed_belief_min_v,
 )
 
 
@@ -114,7 +114,7 @@ def get_chart_data(self, id: int, sensor: Sensor, **kwargs):
         - "resolution" (see :ref:`resolutions`)
         - "most_recent_beliefs_only" (if true, returns the most recent belief for each event; if false, returns each belief for each event; defaults to true)
         """
-        kwargs["timed_belief_min_v"] = validate_timed_belief_min_v(db.session)
+        kwargs["timed_belief_min_v"] = get_timed_belief_min_v(db.session)
         return sensor.search_beliefs(as_json=True, **kwargs)
 
     @route("/<id>/chart_annotations", strict_slashes=False)
diff --git a/flexmeasures/api/v3_0/assets.py b/flexmeasures/api/v3_0/assets.py
index 4b123e298a..b90a79bb0b 100644
--- a/flexmeasures/api/v3_0/assets.py
+++ b/flexmeasures/api/v3_0/assets.py
@@ -48,7 +48,7 @@
     flatten_unique,
 )
 from flexmeasures.utils.validation_utils import (
-    validate_timed_belief_min_v,
+    get_timed_belief_min_v,
 )
 from flexmeasures.ui.utils.view_utils import clear_session, set_session_variables
 from flexmeasures.auth.policy import check_access
@@ -673,7 +673,7 @@ def get_chart_data(self, id: int, asset: GenericAsset, **kwargs):
         Data for use in charts (in case you have the chart specs already).
         """
         sensors = flatten_unique(asset.validate_sensors_to_show())
-        kwargs["timed_belief_min_v"] = validate_timed_belief_min_v(db.session)
+        kwargs["timed_belief_min_v"] = get_timed_belief_min_v(db.session)
         return asset.search_beliefs(sensors=sensors, as_json=True, **kwargs)
 
     @route("/<id>/auditlog")
diff --git a/flexmeasures/ui/templates/base.html b/flexmeasures/ui/templates/base.html
index 8c07697b81..dc98592321 100644
--- a/flexmeasures/ui/templates/base.html
+++ b/flexmeasures/ui/templates/base.html
@@ -227,7 +227,13 @@
                     {% endfor %}
                 </ul>
             </li>
+            {% if active_subpage == "asset_graph" %}
             <div class="form-check form-switch" style="margin-left: auto;">
+                <input class="form-check-input" type="checkbox" id="useMaterializedView" checked title="Reload this graph with latest data instead of using recent cache (updated every {{ mv_refresh_interval }} minutes). This will take longer to load.">
+                <label class="form-check-label" for="useMaterializedView">Use materialized view</label>
+            </div>
+            {% endif %}
+            <div class="form-check form-switch" style="margin-left: 10px;">
                 <input class="form-check-input" type="checkbox" {% if breadcrumb_info['current_asset_view'] == session.get("default_asset_view") %} checked {% endif %} id="defaultAssetView" onchange="setDefaultAssetView(this, '{{ breadcrumb_info["current_asset_view"] }}')">
                 <label class="form-check-label" for="defaultAssetView">Set as my default asset view</label>
             </div>
@@ -893,20 +899,106 @@
      * @param {String} queryEndDate The end date as a string in ISO format, to be used in the query.
      * @return {Promise} A promise that resolves with the data.
      */
-    function fetchGraphDataAndKPIs(previousResult, startDate, endDate, queryStartDate, queryEndDate) {
+    function fetchGraphDataAndKPIs(previousResult, startDate, endDate, queryStartDate, queryEndDate, useMaterializedView=true) {
         if (previousResult && previousResult.start.getTime() === startDate.getTime() && previousResult.end.getTime() === endDate.getTime()){
             return Promise.resolve(previousResult.data);
         } else {
             {% if active_subpage == "asset_graph" and has_kpis %}
                 getAssetKPIs();
             {% endif %}
-            return fetch(dataPath + '/chart_data?event_starts_after=' + queryStartDate + '&event_ends_before=' + queryEndDate, {
+            return fetch(dataPath + '/chart_data?event_starts_after=' + queryStartDate + '&event_ends_before=' + queryEndDate + '&use_materialized_view=' + useMaterializedView, {
                     method: "GET",
                     headers: { "Content-Type": "application/json" },
                     signal: signal,
             }).then(response => response.json());
         }
     }
+
+    const useMaterializedViewCheckbox = document.getElementById("useMaterializedView");
+    useMaterializedViewCheckbox.addEventListener("change", function() {
+        toggleMaterializedView();
+    });
+
+    // Toggle materialized view usage for timely beliefs
+    function toggleMaterializedView() {
+        // Get the checked status of the checkbox
+        const isChecked = useMaterializedViewCheckbox.checked;
+        const pickerStartDate = picker.getStartDate().toJSDate();
+        const queryStartDate= encodeURIComponent(toIsoStringWithOffset(pickerStartDate));
+        var queryEndDate = picker.getEndDate();
+        queryEndDate.setDate(queryEndDate.getDate() + 1);
+        queryEndDate = encodeURIComponent(toIsoStringWithOffset(queryEndDate.toJSDate()));
+        // Since we are going to make a call anyway so we'll send these values as null
+        const startDate = null;
+        const endDate = null;
+        previousResult = null;
+
+        $("#spinner").show();
+        if (isChecked) {
+            console.log("Checked.")
+            // fetchGraphDataAndKPIs(previousResult, startDate, endDate, queryStartDate, queryEndDate, true);
+            Promise.all([
+                fetchGraphDataAndKPIs(previousResult, startDate, endDate, queryStartDate, queryEndDate, true),
+                /**
+                // Fetch annotations
+                fetch(dataPath + '/chart_annotations?event_starts_after=' + queryStartDate + '&event_ends_before=' + queryEndDate, {
+                    method: "GET",
+                    headers: {"Content-Type": "application/json"},
+                    signal: signal,
+                })
+                .then(function(response) { return response.json(); }),
+                */
+
+                // Embed chart
+                embedAndLoad(chartSpecsPath + 'event_starts_after=' + queryStartDate + '&event_ends_before=' + queryEndDate + '&', elementId, datasetName, previousResult, startDate, endDate),
+            ]).then(function(result) {
+                $("#spinner").hide();
+                vegaView.change(datasetName, vega.changeset().remove(vega.truthy).insert(result[0])).resize().run();
+                previousResult = {
+                    start: startDate,
+                    end: endDate,
+                    data: result[0]
+                };
+                checkSourceMasking(previousResult.data);
+                playBackDataLoadedForKnownDateRange = false;
+                /**
+                vegaView.change(datasetName + '_annotations', vega.changeset().remove(vega.truthy).insert(result[1])).resize().run();
+                */
+            }).catch(console.error);
+        }
+        else {
+            // fetchGraphDataAndKPIs(previousResult, startDate, endDate, queryStartDate, queryEndDate, false);
+            Promise.all([
+                fetchGraphDataAndKPIs(previousResult, startDate, endDate, queryStartDate, queryEndDate, false),
+                /**
+                // Fetch annotations
+                fetch(dataPath + '/chart_annotations?event_starts_after=' + queryStartDate + '&event_ends_before=' + queryEndDate, {
+                    method: "GET",
+                    headers: {"Content-Type": "application/json"},
+                    signal: signal,
+                })
+                .then(function(response) { return response.json(); }),
+                */
+
+                // Embed chart
+                embedAndLoad(chartSpecsPath + 'event_starts_after=' + queryStartDate + '&event_ends_before=' + queryEndDate + '&', elementId, datasetName, previousResult, startDate, endDate),
+            ]).then(function(result) {
+                $("#spinner").hide();
+                vegaView.change(datasetName, vega.changeset().remove(vega.truthy).insert(result[0])).resize().run();
+                previousResult = {
+                    start: startDate,
+                    end: endDate,
+                    data: result[0]
+                };
+                checkSourceMasking(previousResult.data);
+                playBackDataLoadedForKnownDateRange = false;
+                /**
+                vegaView.change(datasetName + '_annotations', vega.changeset().remove(vega.truthy).insert(result[1])).resize().run();
+                */
+            }).catch(console.error);
+        }
+        $("#spinner").hide();
+    }
     
     {% if active_subpage == "asset_graph" and has_kpis %}
     function getAssetKPIs() {
diff --git a/flexmeasures/ui/views/assets/views.py b/flexmeasures/ui/views/assets/views.py
index d01cf18501..d513b46057 100644
--- a/flexmeasures/ui/views/assets/views.py
+++ b/flexmeasures/ui/views/assets/views.py
@@ -363,12 +363,16 @@ def graphs(self, id: str, start_time=None, end_time=None):
         asset_form = AssetForm()
         asset_form.with_options()
         asset_form.process(obj=asset)
+        mv_refresh_interval = current_app.config.get(
+            "FLEXMEASURES_MVIEW_UPDATE_INTERVAL", None
+        )
 
         return render_flexmeasures_template(
             "assets/asset_graph.html",
             asset=asset,
             has_kpis=has_kpis,
             asset_kpis=asset_kpis,
+            mv_refresh_interval=mv_refresh_interval,
             current_page="Graphs",
         )
 
diff --git a/flexmeasures/utils/config_defaults.py b/flexmeasures/utils/config_defaults.py
index a4afa4a07c..ce323b26e9 100644
--- a/flexmeasures/utils/config_defaults.py
+++ b/flexmeasures/utils/config_defaults.py
@@ -21,6 +21,7 @@ class Config(object):
     DEBUG: bool = False
     LOGGING_LEVEL: int = logging.WARNING
     SECRET_KEY: str | None = None
+    FLEXMEASURES_MVIEW_UPDATE_INTERVAL: int | None = None
 
     FLEXMEASURES_ENV_DEFAULT = "production"
 
diff --git a/flexmeasures/utils/validation_utils.py b/flexmeasures/utils/validation_utils.py
index 183d967feb..5b3aec5eb9 100644
--- a/flexmeasures/utils/validation_utils.py
+++ b/flexmeasures/utils/validation_utils.py
@@ -1,6 +1,5 @@
 import re
 from sqlalchemy import MetaData, Table, Column, Integer, DateTime, Interval
-from sqlalchemy.sql import text
 
 
 def validate_color_hex(value):
@@ -55,25 +54,8 @@ def validate_url(value):
     return value
 
 
-def validate_timed_belief_min_v(session) -> Table | None:
-    """Define the structure of the timed_belief_min_v materialized view if it exists."""
-    # Check if materialized view exists
-    result = session.execute(
-        text(
-            """
-            SELECT EXISTS (
-                SELECT FROM information_schema.tables
-                WHERE table_name = 'timed_belief_min_v'
-                AND table_schema = 'public'
-            );
-        """
-        )
-    )
-
-    exists = result.scalar()
-    if not exists:
-        return None
-    print("Using timed_belief_min_v materialized view for optimized queries.")
+def get_timed_belief_min_v(session) -> Table | None:
+    """Define the structure of the timed_belief_min_v materialized view."""
 
     # Only create the table definition if it exists
     metadata = MetaData()

From fd41966d54877f74b61b9d539f4e677fc70b0e14 Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Mon, 25 Aug 2025 19:59:40 +0500
Subject: [PATCH 04/12] Resolved comments.

---
 documentation/configuration.rst               | 11 +++++++++-
 flexmeasures/api/dev/sensors.py               |  2 +-
 flexmeasures/api/v3_0/assets.py               |  2 +-
 flexmeasures/cli/db_ops.py                    | 22 +++++++++++++------
 .../timed_beliefs_materialized_views.py       |  8 +++++++
 .../data/schemas/tests/test_input_schema.py   |  2 +-
 flexmeasures/utils/validation_utils.py        |  2 +-
 7 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/documentation/configuration.rst b/documentation/configuration.rst
index da8c20c214..9ef69c4481 100644
--- a/documentation/configuration.rst
+++ b/documentation/configuration.rst
@@ -671,4 +671,13 @@ FLEXMEASURES_API_SUNSET_LINK
 
 Allow to override the default sunset link for your clients.
 
-Default: ``None`` (defaults are set internally for each sunset API version, e.g. ``"https://flexmeasures.readthedocs.io/en/v0.13.0/api/v2_0.html"`` for v2.0)
\ No newline at end of file
+Default: ``None`` (defaults are set internally for each sunset API version, e.g. ``"https://flexmeasures.readthedocs.io/en/v0.13.0/api/v2_0.html"`` for v2.0)
+
+Perforamance optimizations
+----------------------------
+
+FLEXMEASURES_MVIEW_UPDATE_INTERVAL
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Interval in minutes to refresh the materialized views in the background.
+
+Default: ``0`` (minutes)
diff --git a/flexmeasures/api/dev/sensors.py b/flexmeasures/api/dev/sensors.py
index 75171eff44..7a452411a9 100644
--- a/flexmeasures/api/dev/sensors.py
+++ b/flexmeasures/api/dev/sensors.py
@@ -115,7 +115,7 @@ def get_chart_data(self, id: int, sensor: Sensor, **kwargs):
         - "resolution" (see :ref:`resolutions`)
         - "most_recent_beliefs_only" (if true, returns the most recent belief for each event; if false, returns each belief for each event; defaults to true)
         """
-        kwargs["timed_belief_min_v"] = get_timed_belief_min_v(db.session)
+        kwargs["timed_belief_min_v"] = get_timed_belief_min_v()
         return sensor.search_beliefs(as_json=True, **kwargs)
 
     @route("/<id>/chart_annotations", strict_slashes=False)
diff --git a/flexmeasures/api/v3_0/assets.py b/flexmeasures/api/v3_0/assets.py
index ae460053c2..5f693755d8 100644
--- a/flexmeasures/api/v3_0/assets.py
+++ b/flexmeasures/api/v3_0/assets.py
@@ -674,7 +674,7 @@ def get_chart_data(self, id: int, asset: GenericAsset, **kwargs):
         Data for use in charts (in case you have the chart specs already).
         """
         sensors = flatten_unique(asset.validate_sensors_to_show())
-        kwargs["timed_belief_min_v"] = get_timed_belief_min_v(db.session)
+        kwargs["timed_belief_min_v"] = get_timed_belief_min_v()
         return asset.search_beliefs(sensors=sensors, as_json=True, **kwargs)
 
     @route("/<id>/auditlog")
diff --git a/flexmeasures/cli/db_ops.py b/flexmeasures/cli/db_ops.py
index 01c04a41cf..8977acb288 100644
--- a/flexmeasures/cli/db_ops.py
+++ b/flexmeasures/cli/db_ops.py
@@ -100,28 +100,36 @@ def restore(file: str):
 @with_appcontext
 @click.option("--concurrent", is_flag=True, default=False)
 def refresh_materialized_views(concurrent: bool):
-    """Refresh materialized views for better query performance."""
+    """
+    Refresh the materialized views for getting the most recent data.
+    By default, this locks the materialized view for the duration of the refresh.
+    Use the --concurrent option to avoid locking, at the cost of higher resource usage and
+    the requirement that a unique index exists on the materialized view.
+    """
     from sqlalchemy import text
 
     refresh_type = "CONCURRENTLY" if concurrent else ""
     import time
 
     start_time = time.time()
-    click.echo(
-        f"Refreshing materialized views {'CONCURRENTLY' if concurrent else 'without concurrency'}..."
+    click.secho(
+        f"Refreshing materialized views {'CONCURRENTLY' if concurrent else 'without concurrency'}...",
+        **MsgStyle.INFO,
     )
     try:
         db.session.execute(
-            text(f"REFRESH MATERIALIZED {refresh_type} VIEW timed_belief_min_v;")
+            text(f"REFRESH MATERIALIZED VIEW {refresh_type} timed_belief_min_v;")
         )
         db.session.commit()
         elapsed_time = time.time() - start_time
-        click.echo(
-            f"✓ Materialized views refreshed successfully in {elapsed_time:.2f} seconds"
+        click.secho(
+            f"✓ Materialized views refreshed successfully in {elapsed_time:.2f} seconds",
+            **MsgStyle.SUCCESS,
         )
     except Exception as e:
         db.session.rollback()
-        click.echo(f"✗ Error refreshing materialized views: {e}")
+        click.secho(f"✗ Error refreshing materialized views: {e}", **MsgStyle.ERROR)
+        raise click.Abort()
 
 
 app.cli.add_command(fm_db_ops)
diff --git a/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py b/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py
index f4aa64e4d5..3bc5a8657c 100644
--- a/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py
+++ b/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py
@@ -58,6 +58,14 @@ def upgrade():
     """
     )
 
+    # Create a unique index to allow concurrent refreshes
+    op.execute(
+        """
+        CREATE UNIQUE INDEX idx_timed_belief_min_v_unique
+        ON timed_belief_min_v(sensor_id, event_start, source_id);
+    """
+    )
+
 
 def downgrade():
     op.execute("DROP MATERIALIZED VIEW IF EXISTS timed_belief_min_v CASCADE;")
diff --git a/flexmeasures/data/schemas/tests/test_input_schema.py b/flexmeasures/data/schemas/tests/test_input_schema.py
index 97bcdd6ebb..05df9c1e58 100644
--- a/flexmeasures/data/schemas/tests/test_input_schema.py
+++ b/flexmeasures/data/schemas/tests/test_input_schema.py
@@ -19,7 +19,7 @@ def test_input_schema():
     excluded_arg_names = [
         "as_json",  # used in Sensor.search_beliefs but not in TimedBelief.search
         "timed_belief_min_v",  # used in Sensor.search_beliefs but not in TimedBelief.search
-        "use_materialized_view",  # used in Sensor.search_beliefs but not in
+        "use_materialized_view",  # used in Sensor.search_beliefs as well as in TimedBelief.search
         "compress_json",  # used in Sensor.search_beliefs but not in TimedBelief.search
     ]
 
diff --git a/flexmeasures/utils/validation_utils.py b/flexmeasures/utils/validation_utils.py
index 5b3aec5eb9..558180e77e 100644
--- a/flexmeasures/utils/validation_utils.py
+++ b/flexmeasures/utils/validation_utils.py
@@ -54,7 +54,7 @@ def validate_url(value):
     return value
 
 
-def get_timed_belief_min_v(session) -> Table | None:
+def get_timed_belief_min_v() -> Table | None:
     """Define the structure of the timed_belief_min_v materialized view."""
 
     # Only create the table definition if it exists

From e483d982367fd1283f9c4e8778ee49378200a23b Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Mon, 25 Aug 2025 20:15:16 +0500
Subject: [PATCH 05/12] Tiny refactor.

---
 flexmeasures/utils/validation_utils.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flexmeasures/utils/validation_utils.py b/flexmeasures/utils/validation_utils.py
index 558180e77e..92832e3090 100644
--- a/flexmeasures/utils/validation_utils.py
+++ b/flexmeasures/utils/validation_utils.py
@@ -54,7 +54,7 @@ def validate_url(value):
     return value
 
 
-def get_timed_belief_min_v() -> Table | None:
+def get_timed_belief_min_v() -> Table:
     """Define the structure of the timed_belief_min_v materialized view."""
 
     # Only create the table definition if it exists

From 74d66518d3823cabff8de59dacf15d49d5e046ce Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Tue, 2 Sep 2025 14:03:10 +0500
Subject: [PATCH 06/12] Update documentation/configuration.rst

Co-authored-by: Felix Claessen <30658763+Flix6x@users.noreply.github.com>
Signed-off-by: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
---
 documentation/configuration.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/documentation/configuration.rst b/documentation/configuration.rst
index 9ef69c4481..63b3691b03 100644
--- a/documentation/configuration.rst
+++ b/documentation/configuration.rst
@@ -673,7 +673,7 @@ Allow to override the default sunset link for your clients.
 
 Default: ``None`` (defaults are set internally for each sunset API version, e.g. ``"https://flexmeasures.readthedocs.io/en/v0.13.0/api/v2_0.html"`` for v2.0)
 
-Perforamance optimizations
+Performance optimizations
 ----------------------------
 
 FLEXMEASURES_MVIEW_UPDATE_INTERVAL

From c65ef8c08c0465a1e0594180dd0df2b7ddb4b46a Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Tue, 2 Sep 2025 20:36:30 +0500
Subject: [PATCH 07/12] Moved get_timed_belief_min_v and some other small
 changes.

---
 documentation/configuration.rst         |  6 ++--
 flexmeasures/api/dev/sensors.py         |  6 ++--
 flexmeasures/api/v3_0/assets.py         |  6 ++--
 flexmeasures/data/config.py             |  7 ++++-
 flexmeasures/data/models/time_series.py | 38 ++++++++++++++++++++++++-
 flexmeasures/ui/views/assets/views.py   |  2 +-
 flexmeasures/utils/config_defaults.py   |  2 +-
 flexmeasures/utils/validation_utils.py  | 17 -----------
 8 files changed, 52 insertions(+), 32 deletions(-)

diff --git a/documentation/configuration.rst b/documentation/configuration.rst
index 9ef69c4481..902c74ea39 100644
--- a/documentation/configuration.rst
+++ b/documentation/configuration.rst
@@ -676,8 +676,8 @@ Default: ``None`` (defaults are set internally for each sunset API version, e.g.
 Perforamance optimizations
 ----------------------------
 
-FLEXMEASURES_MVIEW_UPDATE_INTERVAL
+FLEXMEASURES_MVIEW_REFRESH_INTERVAL
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Interval in minutes to refresh the materialized views in the background.
+Interval in minutes to refresh the materialized db view which caches the most recent beliefs at a given point in time (for faster queries).
 
-Default: ``0`` (minutes)
+Default: None
diff --git a/flexmeasures/api/dev/sensors.py b/flexmeasures/api/dev/sensors.py
index 7a452411a9..d7a153ba96 100644
--- a/flexmeasures/api/dev/sensors.py
+++ b/flexmeasures/api/dev/sensors.py
@@ -20,9 +20,7 @@
 from flexmeasures.data.models.time_series import Sensor
 from flexmeasures.data.services.annotations import prepare_annotations_for_chart
 from flexmeasures.ui.utils.view_utils import set_session_variables
-from flexmeasures.utils.validation_utils import (
-    get_timed_belief_min_v,
-)
+from flexmeasures.data.config import timed_belief_min_v
 
 
 class SensorAPI(FlaskView):
@@ -115,7 +113,7 @@ def get_chart_data(self, id: int, sensor: Sensor, **kwargs):
         - "resolution" (see :ref:`resolutions`)
         - "most_recent_beliefs_only" (if true, returns the most recent belief for each event; if false, returns each belief for each event; defaults to true)
         """
-        kwargs["timed_belief_min_v"] = get_timed_belief_min_v()
+        kwargs["timed_belief_min_v"] = timed_belief_min_v
         return sensor.search_beliefs(as_json=True, **kwargs)
 
     @route("/<id>/chart_annotations", strict_slashes=False)
diff --git a/flexmeasures/api/v3_0/assets.py b/flexmeasures/api/v3_0/assets.py
index 5f693755d8..180661e465 100644
--- a/flexmeasures/api/v3_0/assets.py
+++ b/flexmeasures/api/v3_0/assets.py
@@ -47,9 +47,7 @@
 from flexmeasures.utils.coding_utils import (
     flatten_unique,
 )
-from flexmeasures.utils.validation_utils import (
-    get_timed_belief_min_v,
-)
+from flexmeasures.data.config import timed_belief_min_v
 from flexmeasures.ui.utils.view_utils import clear_session, set_session_variables
 from flexmeasures.auth.policy import check_access
 from werkzeug.exceptions import Forbidden, Unauthorized
@@ -674,7 +672,7 @@ def get_chart_data(self, id: int, asset: GenericAsset, **kwargs):
         Data for use in charts (in case you have the chart specs already).
         """
         sensors = flatten_unique(asset.validate_sensors_to_show())
-        kwargs["timed_belief_min_v"] = get_timed_belief_min_v()
+        kwargs["timed_belief_min_v"] = timed_belief_min_v
         return asset.search_beliefs(sensors=sensors, as_json=True, **kwargs)
 
     @route("/<id>/auditlog")
diff --git a/flexmeasures/data/config.py b/flexmeasures/data/config.py
index f8c98c6c8e..3d3a741613 100644
--- a/flexmeasures/data/config.py
+++ b/flexmeasures/data/config.py
@@ -16,6 +16,7 @@
 )
 Base = None  # type: ignore
 session_options = None
+timed_belief_min_v = None
 
 
 def init_db():
@@ -32,7 +33,7 @@ def init_db():
 def configure_db_for(app: Flask):
     """Call this to configure the database and the tools we use on it for the Flask app.
     This should only be called once in the app's lifetime."""
-    global db, Base
+    global db, Base, timed_belief_min_v
 
     with app.app_context():
         db.init_app(app)
@@ -51,6 +52,10 @@ def configure_db_for(app: Flask):
             forecasting,
         )  # noqa: F401
 
+        from flexmeasures.data.models.time_series import get_timed_belief_min_v
+
+        timed_belief_min_v = get_timed_belief_min_v(db.session)
+
         # This would create db structure based on models, but you should use `flask db upgrade` for that.
         # Base.metadata.create_all(bind=db.engine)
 
diff --git a/flexmeasures/data/models/time_series.py b/flexmeasures/data/models/time_series.py
index 736168431b..1b43565144 100644
--- a/flexmeasures/data/models/time_series.py
+++ b/flexmeasures/data/models/time_series.py
@@ -8,7 +8,17 @@
 from flask import current_app
 
 import pandas as pd
-from sqlalchemy import select, Table
+from sqlalchemy import (
+    select,
+    Table,
+    Column,
+    DateTime,
+    Integer,
+    MetaData,
+    text,
+    Interval,
+)
+from sqlalchemy.orm import Session
 from sqlalchemy.ext.declarative import declared_attr
 from sqlalchemy.ext.mutable import MutableDict
 from sqlalchemy.schema import UniqueConstraint
@@ -47,6 +57,32 @@
 from flexmeasures.utils.geo_utils import parse_lat_lng
 
 
+def get_timed_belief_min_v(session: Session) -> Table | None:
+    """Define the structure of the timed_belief_min_v materialized view."""
+
+    timed_belief_min_v = session.execute(
+        text(
+            """
+            SELECT *
+            FROM pg_matviews
+            WHERE matviewname = 'timed_belief_min_v';
+        """
+        )
+    ).fetchone()
+    if timed_belief_min_v:
+        metadata = MetaData()
+        timed_belief_min_v = Table(
+            "timed_belief_min_v",
+            metadata,
+            Column("sensor_id", Integer),
+            Column("event_start", DateTime),
+            Column("source_id", Integer),
+            Column("most_recent_belief_horizon", Interval),
+        )
+
+    return timed_belief_min_v
+
+
 class Sensor(db.Model, tb.SensorDBMixin, AuthModelMixin):
     """A sensor measures events."""
 
diff --git a/flexmeasures/ui/views/assets/views.py b/flexmeasures/ui/views/assets/views.py
index 50bf17d310..62a38421b0 100644
--- a/flexmeasures/ui/views/assets/views.py
+++ b/flexmeasures/ui/views/assets/views.py
@@ -356,7 +356,7 @@ def graphs(self, id: str, start_time=None, end_time=None):
         asset_form.with_options()
         asset_form.process(obj=asset)
         mv_refresh_interval = current_app.config.get(
-            "FLEXMEASURES_MVIEW_UPDATE_INTERVAL", None
+            "FLEXMEASURES_MVIEW_REFRESH_INTERVAL", None
         )
 
         return render_flexmeasures_template(
diff --git a/flexmeasures/utils/config_defaults.py b/flexmeasures/utils/config_defaults.py
index ce323b26e9..8df4fb6f5b 100644
--- a/flexmeasures/utils/config_defaults.py
+++ b/flexmeasures/utils/config_defaults.py
@@ -21,7 +21,7 @@ class Config(object):
     DEBUG: bool = False
     LOGGING_LEVEL: int = logging.WARNING
     SECRET_KEY: str | None = None
-    FLEXMEASURES_MVIEW_UPDATE_INTERVAL: int | None = None
+    FLEXMEASURES_MVIEW_REFRESH_INTERVAL: int | None = None
 
     FLEXMEASURES_ENV_DEFAULT = "production"
 
diff --git a/flexmeasures/utils/validation_utils.py b/flexmeasures/utils/validation_utils.py
index 92832e3090..50935ed544 100644
--- a/flexmeasures/utils/validation_utils.py
+++ b/flexmeasures/utils/validation_utils.py
@@ -1,5 +1,4 @@
 import re
-from sqlalchemy import MetaData, Table, Column, Integer, DateTime, Interval
 
 
 def validate_color_hex(value):
@@ -52,19 +51,3 @@ def validate_url(value):
         )
 
     return value
-
-
-def get_timed_belief_min_v() -> Table:
-    """Define the structure of the timed_belief_min_v materialized view."""
-
-    # Only create the table definition if it exists
-    metadata = MetaData()
-    timed_belief_min_v = Table(
-        "timed_belief_min_v",
-        metadata,
-        Column("sensor_id", Integer),
-        Column("event_start", DateTime),
-        Column("source_id", Integer),
-        Column("most_recent_belief_horizon", Interval),
-    )
-    return timed_belief_min_v

From 942380cba6c069ec82719ea9290a3d1273b201ae Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Wed, 3 Sep 2025 20:03:12 +0500
Subject: [PATCH 08/12] Moved get_timed_belief_min_v to timely-beliefs repo.

---
 flexmeasures/data/config.py             | 13 +++++++---
 flexmeasures/data/models/time_series.py | 33 -------------------------
 2 files changed, 10 insertions(+), 36 deletions(-)

diff --git a/flexmeasures/data/config.py b/flexmeasures/data/config.py
index 3d3a741613..414f13f814 100644
--- a/flexmeasures/data/config.py
+++ b/flexmeasures/data/config.py
@@ -52,9 +52,16 @@ def configure_db_for(app: Flask):
             forecasting,
         )  # noqa: F401
 
-        from flexmeasures.data.models.time_series import get_timed_belief_min_v
-
-        timed_belief_min_v = get_timed_belief_min_v(db.session)
+        import timely_beliefs.utils as tb_utils
+
+        try:
+            timed_belief_min_v = tb_utils.get_timed_belief_min_v(db.session)
+        except Exception:
+            timed_belief_min_v = None
+            app.logger.warning(
+                "Could not determine timed_belief_min_v. Do you have timely-beliefs installed and is the latest version?"
+                " Beliefs will be retrieved from the actual table instead of the materialized view.",
+            )
 
         # This would create db structure based on models, but you should use `flask db upgrade` for that.
         # Base.metadata.create_all(bind=db.engine)
diff --git a/flexmeasures/data/models/time_series.py b/flexmeasures/data/models/time_series.py
index b42fee7839..49d45919e4 100644
--- a/flexmeasures/data/models/time_series.py
+++ b/flexmeasures/data/models/time_series.py
@@ -11,14 +11,7 @@
 from sqlalchemy import (
     select,
     Table,
-    Column,
-    DateTime,
-    Integer,
-    MetaData,
-    text,
-    Interval,
 )
-from sqlalchemy.orm import Session
 from sqlalchemy.ext.declarative import declared_attr
 from sqlalchemy.ext.mutable import MutableDict
 from sqlalchemy.schema import UniqueConstraint
@@ -58,32 +51,6 @@
 from flexmeasures.utils.geo_utils import parse_lat_lng
 
 
-def get_timed_belief_min_v(session: Session) -> Table | None:
-    """Define the structure of the timed_belief_min_v materialized view."""
-
-    timed_belief_min_v = session.execute(
-        text(
-            """
-            SELECT *
-            FROM pg_matviews
-            WHERE matviewname = 'timed_belief_min_v';
-        """
-        )
-    ).fetchone()
-    if timed_belief_min_v:
-        metadata = MetaData()
-        timed_belief_min_v = Table(
-            "timed_belief_min_v",
-            metadata,
-            Column("sensor_id", Integer),
-            Column("event_start", DateTime),
-            Column("source_id", Integer),
-            Column("most_recent_belief_horizon", Interval),
-        )
-
-    return timed_belief_min_v
-
-
 class Sensor(db.Model, tb.SensorDBMixin, AuthModelMixin, OrderByIdMixin):
     """A sensor measures events."""
 

From b6ca3d457e4d8763274b60c9214241ab857fbaa1 Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Thu, 4 Sep 2025 11:12:55 +0500
Subject: [PATCH 09/12] Updated base.html according to materialized view
 refresh interval

---
 flexmeasures/ui/templates/base.html | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/flexmeasures/ui/templates/base.html b/flexmeasures/ui/templates/base.html
index f2832b1d9d..1172043039 100644
--- a/flexmeasures/ui/templates/base.html
+++ b/flexmeasures/ui/templates/base.html
@@ -227,15 +227,23 @@
                     {% endfor %}
                 </ul>
             </li>
-            {% if active_subpage == "asset_graph" %}
-            <div class="form-check form-switch" style="margin-left: auto;">
-                <input class="form-check-input" type="checkbox" id="useMaterializedView" checked title="Reload this graph with latest data instead of using recent cache (updated every {{ mv_refresh_interval }} minutes). This will take longer to load.">
-                <label class="form-check-label" for="useMaterializedView">Use materialized view</label>
-            </div>
-            {% endif %}
-            <div class="form-check form-switch" style="margin-left: 10px;">
-                <input class="form-check-input" type="checkbox" {% if breadcrumb_info['current_asset_view'] == session.get("default_asset_view") %} checked {% endif %} id="defaultAssetView" onchange="setDefaultAssetView(this, '{{ breadcrumb_info["current_asset_view"] }}')">
-                <label class="form-check-label" for="defaultAssetView">Set as my default asset view</label>
+            <div style="margin-left: auto;" class="d-flex align-items-center">
+                {# Option to refresh data from materialized view if applicable #}
+                {# Note: the checkbox is checked by default, meaning the materialized view is used (for faster loading) #}
+                {# Unchecking it will reload the graph with fresh data, which may take more time #}
+                {# This option is only shown when a materialized view refresh interval is configured #}
+                {% if active_subpage == "asset_graph" and mv_refresh_interval %}
+                <div class="form-check form-switch">
+                    <input class="form-check-input" type="checkbox" id="useMaterializedView" checked title="Bypass cached data and reload this graph with real-time results.
+Cached data is refreshed every {{ mv_refresh_interval }} minutes for faster loading.
+Loading fresh data will take additional time.">
+                    <label class="form-check-label" for="useMaterializedView">Refresh data</label>
+                </div>
+                {% endif %}
+                <div class="form-check form-switch" style="margin-left: 10px;">
+                    <input class="form-check-input" type="checkbox" {% if breadcrumb_info['current_asset_view'] == session.get("default_asset_view") %} checked {% endif %} id="defaultAssetView" onchange="setDefaultAssetView(this, '{{ breadcrumb_info["current_asset_view"] }}')">
+                    <label class="form-check-label" for="defaultAssetView">Set as my default asset view</label>
+                </div>
             </div>
             {% endif %}
         </ol>

From e2140a16b1efe80bae51f44abb8f8b066f2cca82 Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Thu, 4 Sep 2025 11:29:44 +0500
Subject: [PATCH 10/12] Renamed timed_belief_min_v to most_recent_beliefs_mview

---
 flexmeasures/api/dev/sensors.py                  |  4 ++--
 flexmeasures/api/v3_0/assets.py                  |  4 ++--
 flexmeasures/cli/db_ops.py                       |  2 +-
 flexmeasures/data/config.py                      | 11 ++++++-----
 .../versions/timed_beliefs_materialized_views.py | 16 ++++++++--------
 flexmeasures/data/models/generic_assets.py       |  4 ++--
 flexmeasures/data/models/time_series.py          |  8 ++++----
 .../data/schemas/tests/test_input_schema.py      |  2 +-
 8 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/flexmeasures/api/dev/sensors.py b/flexmeasures/api/dev/sensors.py
index d7a153ba96..b720273ccb 100644
--- a/flexmeasures/api/dev/sensors.py
+++ b/flexmeasures/api/dev/sensors.py
@@ -20,7 +20,7 @@
 from flexmeasures.data.models.time_series import Sensor
 from flexmeasures.data.services.annotations import prepare_annotations_for_chart
 from flexmeasures.ui.utils.view_utils import set_session_variables
-from flexmeasures.data.config import timed_belief_min_v
+from flexmeasures.data.config import most_recent_beliefs_mview
 
 
 class SensorAPI(FlaskView):
@@ -113,7 +113,7 @@ def get_chart_data(self, id: int, sensor: Sensor, **kwargs):
         - "resolution" (see :ref:`resolutions`)
         - "most_recent_beliefs_only" (if true, returns the most recent belief for each event; if false, returns each belief for each event; defaults to true)
         """
-        kwargs["timed_belief_min_v"] = timed_belief_min_v
+        kwargs["most_recent_beliefs_mview"] = most_recent_beliefs_mview
         return sensor.search_beliefs(as_json=True, **kwargs)
 
     @route("/<id>/chart_annotations", strict_slashes=False)
diff --git a/flexmeasures/api/v3_0/assets.py b/flexmeasures/api/v3_0/assets.py
index c562a77afe..363e33628c 100644
--- a/flexmeasures/api/v3_0/assets.py
+++ b/flexmeasures/api/v3_0/assets.py
@@ -48,7 +48,7 @@
 from flexmeasures.utils.coding_utils import (
     flatten_unique,
 )
-from flexmeasures.data.config import timed_belief_min_v
+from flexmeasures.data.config import most_recent_beliefs_mview
 from flexmeasures.ui.utils.view_utils import clear_session, set_session_variables
 from flexmeasures.auth.policy import check_access
 from werkzeug.exceptions import Forbidden, Unauthorized
@@ -710,7 +710,7 @@ def get_chart_data(self, id: int, asset: GenericAsset, **kwargs):
         Data for use in charts (in case you have the chart specs already).
         """
         sensors = flatten_unique(asset.validate_sensors_to_show())
-        kwargs["timed_belief_min_v"] = timed_belief_min_v
+        kwargs["most_recent_beliefs_mview"] = most_recent_beliefs_mview
         return asset.search_beliefs(sensors=sensors, as_json=True, **kwargs)
 
     @route("/<id>/auditlog")
diff --git a/flexmeasures/cli/db_ops.py b/flexmeasures/cli/db_ops.py
index 8977acb288..6bb649eeaa 100644
--- a/flexmeasures/cli/db_ops.py
+++ b/flexmeasures/cli/db_ops.py
@@ -118,7 +118,7 @@ def refresh_materialized_views(concurrent: bool):
     )
     try:
         db.session.execute(
-            text(f"REFRESH MATERIALIZED VIEW {refresh_type} timed_belief_min_v;")
+            text(f"REFRESH MATERIALIZED VIEW {refresh_type} most_recent_beliefs_mview;")
         )
         db.session.commit()
         elapsed_time = time.time() - start_time
diff --git a/flexmeasures/data/config.py b/flexmeasures/data/config.py
index 414f13f814..55a78ed9a7 100644
--- a/flexmeasures/data/config.py
+++ b/flexmeasures/data/config.py
@@ -16,7 +16,7 @@
 )
 Base = None  # type: ignore
 session_options = None
-timed_belief_min_v = None
+most_recent_beliefs_mview = None
 
 
 def init_db():
@@ -33,7 +33,7 @@ def init_db():
 def configure_db_for(app: Flask):
     """Call this to configure the database and the tools we use on it for the Flask app.
     This should only be called once in the app's lifetime."""
-    global db, Base, timed_belief_min_v
+    global db, Base, most_recent_beliefs_mview
 
     with app.app_context():
         db.init_app(app)
@@ -55,11 +55,12 @@ def configure_db_for(app: Flask):
         import timely_beliefs.utils as tb_utils
 
         try:
-            timed_belief_min_v = tb_utils.get_timed_belief_min_v(db.session)
+            most_recent_beliefs_mview = tb_utils.get_most_recent_beliefs_mview(
+                db.session
+            )
         except Exception:
-            timed_belief_min_v = None
             app.logger.warning(
-                "Could not determine timed_belief_min_v. Do you have timely-beliefs installed and is the latest version?"
+                "Could not determine most_recent_beliefs_mview. Do you have timely-beliefs installed and is the latest version?"
                 " Beliefs will be retrieved from the actual table instead of the materialized view.",
             )
 
diff --git a/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py b/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py
index 3bc5a8657c..d82ed668ff 100644
--- a/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py
+++ b/flexmeasures/data/migrations/versions/timed_beliefs_materialized_views.py
@@ -19,7 +19,7 @@ def upgrade():
     # Create the materialized view with proper alias
     op.execute(
         """
-        CREATE MATERIALIZED VIEW timed_belief_min_v AS
+        CREATE MATERIALIZED VIEW most_recent_beliefs_mview AS
         SELECT *
         FROM (
             SELECT
@@ -46,26 +46,26 @@ def upgrade():
     # Create indexes
     op.execute(
         """
-        CREATE INDEX idx_timed_belief_min_v_sensor_event
-        ON timed_belief_min_v(sensor_id, event_start);
+        CREATE INDEX idx_most_recent_beliefs_mview_sensor_event
+        ON most_recent_beliefs_mview(sensor_id, event_start);
     """
     )
 
     op.execute(
         """
-        CREATE INDEX idx_timed_belief_min_v_event_start
-        ON timed_belief_min_v(event_start);
+        CREATE INDEX idx_most_recent_beliefs_mview_event_start
+        ON most_recent_beliefs_mview(event_start);
     """
     )
 
     # Create a unique index to allow concurrent refreshes
     op.execute(
         """
-        CREATE UNIQUE INDEX idx_timed_belief_min_v_unique
-        ON timed_belief_min_v(sensor_id, event_start, source_id);
+        CREATE UNIQUE INDEX idx_most_recent_beliefs_mview_unique
+        ON most_recent_beliefs_mview(sensor_id, event_start, source_id);
     """
     )
 
 
 def downgrade():
-    op.execute("DROP MATERIALIZED VIEW IF EXISTS timed_belief_min_v CASCADE;")
+    op.execute("DROP MATERIALIZED VIEW IF EXISTS most_recent_beliefs_mview CASCADE;")
diff --git a/flexmeasures/data/models/generic_assets.py b/flexmeasures/data/models/generic_assets.py
index 78666aee3b..1178ebce9d 100644
--- a/flexmeasures/data/models/generic_assets.py
+++ b/flexmeasures/data/models/generic_assets.py
@@ -649,7 +649,7 @@ def search_beliefs(  # noqa C901
         compress_json: bool = False,
         resolution: timedelta | None = None,
         use_materialized_view: bool = True,
-        timed_belief_min_v: Table | None = None,
+        most_recent_beliefs_mview: Table | None = None,
     ) -> BeliefsDataFrame | str:
         """Search all beliefs about events for all sensors of this asset
 
@@ -691,7 +691,7 @@ def search_beliefs(  # noqa C901
                 one_deterministic_belief_per_event_per_source=True,
                 resolution=resolution,
                 use_materialized_view=use_materialized_view,
-                timed_belief_min_v=timed_belief_min_v,
+                most_recent_beliefs_mview=most_recent_beliefs_mview,
             )
         if as_json and not compress_json:
             from flexmeasures.data.services.time_series import simplify_index
diff --git a/flexmeasures/data/models/time_series.py b/flexmeasures/data/models/time_series.py
index 49d45919e4..34b8f6718e 100644
--- a/flexmeasures/data/models/time_series.py
+++ b/flexmeasures/data/models/time_series.py
@@ -360,7 +360,7 @@ def search_beliefs(  # noqa: C901
         compress_json: bool = False,
         resolution: str | timedelta | None = None,
         use_materialized_view: bool = True,
-        timed_belief_min_v: Table | None = None,
+        most_recent_beliefs_mview: Table | None = None,
     ) -> tb.BeliefsDataFrame | str:
         """Search all beliefs about events for this sensor.
 
@@ -407,7 +407,7 @@ def search_beliefs(  # noqa: C901
             one_deterministic_belief_per_event_per_source=one_deterministic_belief_per_event_per_source,
             resolution=resolution,
             use_materialized_view=use_materialized_view,
-            timed_belief_min_v=timed_belief_min_v,
+            most_recent_beliefs_mview=most_recent_beliefs_mview,
         )
         if as_json and not compress_json:
             df = bdf.reset_index()
@@ -812,7 +812,7 @@ def search(
         resolution: str | timedelta = None,
         sum_multiple: bool = True,
         use_materialized_view: bool = True,
-        timed_belief_min_v: Table | None = None,
+        most_recent_beliefs_mview: Table | None = None,
     ) -> tb.BeliefsDataFrame | dict[str, tb.BeliefsDataFrame]:
         """Search all beliefs about events for the given sensors.
 
@@ -897,7 +897,7 @@ def search(
                 custom_filter_criteria=source_criteria,
                 custom_join_targets=custom_join_targets,
                 use_materialized_view=use_materialized_view,
-                timed_belief_min_v=timed_belief_min_v,
+                most_recent_beliefs_mview=most_recent_beliefs_mview,
             )
             if use_latest_version_per_event:
                 bdf = keep_latest_version(
diff --git a/flexmeasures/data/schemas/tests/test_input_schema.py b/flexmeasures/data/schemas/tests/test_input_schema.py
index 05df9c1e58..91e7d847f8 100644
--- a/flexmeasures/data/schemas/tests/test_input_schema.py
+++ b/flexmeasures/data/schemas/tests/test_input_schema.py
@@ -18,7 +18,7 @@ def test_input_schema():
     # These arguments are not mapped to a field at all (state a reason)
     excluded_arg_names = [
         "as_json",  # used in Sensor.search_beliefs but not in TimedBelief.search
-        "timed_belief_min_v",  # used in Sensor.search_beliefs but not in TimedBelief.search
+        "most_recent_beliefs_mview",  # used in Sensor.search_beliefs but not in TimedBelief.search
         "use_materialized_view",  # used in Sensor.search_beliefs as well as in TimedBelief.search
         "compress_json",  # used in Sensor.search_beliefs but not in TimedBelief.search
     ]

From fa522faba3f43804039aaf47fb2845a0189451a0 Mon Sep 17 00:00:00 2001
From: Muhammad-Moiz626 <muhammadmoiz4843@gmail.com>
Date: Thu, 4 Sep 2025 11:48:28 +0500
Subject: [PATCH 11/12] Added changelog.

---
 documentation/changelog.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/documentation/changelog.rst b/documentation/changelog.rst
index 78293e1f38..e296371a40 100644
--- a/documentation/changelog.rst
+++ b/documentation/changelog.rst
@@ -15,6 +15,7 @@ New features
 * Display KPIs for asset sensors with daily event resolution [see `PR #1608 <https://github.com/FlexMeasures/flexmeasures/pull/1608>`_, `PR #1634 <https://github.com/FlexMeasures/flexmeasures/pull/1634>`_ and `PR #1656 <https://github.com/FlexMeasures/flexmeasures/pull/1656>`_]
 * Improved timestamp on sensor detail page to be more friendly [see `PR #1632 <https://www.github.com/FlexMeasures/flexmeasures/pull/1632>`_]
 * Asset types support: new API endpoint (`GET /assets/types`), better docs and fix CLI command `flexmeasures show asset-types` [see `PR #1663 <https://github.com/FlexMeasures/flexmeasures/pull/1663>`_]
+* Added Materialized View for latest beliefs per sensor to speed up data loading [see `PR #1671 <https://github.com/FlexMeasures/flexmeasures/pull/1671>`_]
 
 Infrastructure / Support
 ----------------------

From aabd536a87f3488600adad996eaed7302749fb06 Mon Sep 17 00:00:00 2001
From: "F.N. Claessen" <felix@seita.nl>
Date: Mon, 15 Dec 2025 17:01:45 +0100
Subject: [PATCH 12/12] chore: db merge

Signed-off-by: F.N. Claessen <felix@seita.nl>
---
 .../migrations/versions/75a82be1c1d6_merge.py | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 flexmeasures/data/migrations/versions/75a82be1c1d6_merge.py

diff --git a/flexmeasures/data/migrations/versions/75a82be1c1d6_merge.py b/flexmeasures/data/migrations/versions/75a82be1c1d6_merge.py
new file mode 100644
index 0000000000..371a8ea660
--- /dev/null
+++ b/flexmeasures/data/migrations/versions/75a82be1c1d6_merge.py
@@ -0,0 +1,21 @@
+"""merge
+
+Revision ID: 75a82be1c1d6
+Revises: 6cca6c002135, c98798csds8c
+Create Date: 2025-12-15 16:53:05.313298
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = "75a82be1c1d6"
+down_revision = ["6cca6c002135", "c98798csds8c"]
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    pass
+
+
+def downgrade():
+    pass