From aa1bac0d46dce81fbb2e4d0b6bce3e9fd47450bd Mon Sep 17 00:00:00 2001
From: Graham McIntire <graham@mcintire.me>
Date: Thu, 12 Feb 2026 10:16:10 -0600
Subject: [PATCH] perf: batch inserts, selective LiveView reloading, and
 database indexes for scale

Replace individual Repo.insert() with Repo.insert_all() for sensor readings,
interface stats, processor readings, and storage readings in agent channel and
device poller worker. Add partial/composite database indexes for common query
patterns. Dashboard now uses GROUP BY aggregation instead of loading all devices.
DeviceLive.Show only reloads data for the active tab on PubSub events.
DeviceLive.Index debounces status changes and skips quota queries on updates.
Agent polling preloads filtered to monitored sensors/interfaces only.
---
 CHANGELOG.txt                                 |  27 ++
 lib/towerops/agents.ex                        |   5 +-
 lib/towerops/devices.ex                       |  24 +
 lib/towerops/snmp.ex                          |  88 ++++
 lib/towerops/workers/device_poller_worker.ex  | 277 +++++++----
 lib/towerops_web/channels/agent_channel.ex    | 102 ++--
 lib/towerops_web/live/dashboard_live.ex       |  17 +-
 lib/towerops_web/live/device_live/index.ex    |  53 +-
 lib/towerops_web/live/device_live/show.ex     | 230 ++++++---
 ...20260212155105_add_performance_indexes.exs |  39 ++
 .../devices/device_status_counts_test.exs     | 129 +++++
 test/towerops/snmp/batch_insert_test.exs      | 459 ++++++++++++++++++
 12 files changed, 1211 insertions(+), 239 deletions(-)
 create mode 100644 priv/repo/migrations/20260212155105_add_performance_indexes.exs
 create mode 100644 test/towerops/devices/device_status_counts_test.exs
 create mode 100644 test/towerops/snmp/batch_insert_test.exs

diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 58820e59..b5ee4e9d 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,6 +1,33 @@
 CHANGELOG - towerops-web
 ========================
 
+2026-02-12 - perf: performance improvements for scale (batch inserts, indexes, selective reloading)
+  - Files: lib/towerops/snmp.ex, lib/towerops/devices.ex, lib/towerops_web/channels/agent_channel.ex,
+    lib/towerops/workers/device_poller_worker.ex, lib/towerops_web/live/dashboard_live.ex,
+    lib/towerops_web/live/device_live/show.ex, lib/towerops_web/live/device_live/index.ex,
+    lib/towerops/agents.ex, priv/repo/migrations/20260212155105_add_performance_indexes.exs
+
+    Phase 1: Batch data ingestion - replaced individual Repo.insert() calls with Repo.insert_all()
+    for sensor readings, interface stats, processor readings, and storage readings in both
+    agent_channel.ex and device_poller_worker.ex. Added create_*_batch/1 functions to snmp.ex.
+
+    Phase 2: Database indexes - added partial indexes for monitored sensors/interfaces,
+    composite index for devices org+status, partial index for active alerts.
+
+    Phase 3: Dashboard aggregation - replaced loading all devices into memory with
+    Devices.get_device_status_counts/1 GROUP BY query.
+
+    Phase 4: DeviceLive.Show selective updates - split monolithic load_equipment_data into
+    tab-specific loaders (base, tab_nav, overview, ports, logs, backups). PubSub handlers
+    now only reload data relevant to the active tab.
+
+    Phase 5: DeviceLive.Index incremental updates - separated structural changes (create/delete)
+    from status changes. Added debouncing for rapid status changes. Skip reload when viewing
+    discovered tab.
+
+    Phase 6: Agent polling memory optimization - filtered preloads in list_agent_polling_targets
+    to only load monitored sensors and interfaces instead of all.
+
 2026-02-12 - feat: complete WISP vendor coverage (ePMP, Raisecom, Netonix)
   - Files: priv/profiles/os_discovery/epmp.yaml (enhanced), lib/towerops/snmp/profiles/vendors/raisecom.ex (new)
     Completed LibreNMS parity for major WISP equipment vendors. Three improvements:
diff --git a/lib/towerops/agents.ex b/lib/towerops/agents.ex
index 1c084010..a51850af 100644
--- a/lib/towerops/agents.ex
+++ b/lib/towerops/agents.ex
@@ -592,7 +592,10 @@ defmodule Towerops.Agents do
           :agent_assignments,
           :organization,
           site: :organization,
-          snmp_device: [:sensors, :interfaces]
+          snmp_device: [
+            sensors: ^from(s in Towerops.Snmp.Sensor, where: s.monitored == true),
+            interfaces: ^from(i in Towerops.Snmp.Interface, where: i.monitored == true)
+          ]
         ]
       )
 
diff --git a/lib/towerops/devices.ex b/lib/towerops/devices.ex
index dc6cd88d..6139f153 100644
--- a/lib/towerops/devices.ex
+++ b/lib/towerops/devices.ex
@@ -116,6 +116,30 @@ defmodule Towerops.Devices do
     )
   end
 
+  @doc """
+  Returns a map of device status counts for an organization.
+
+  Uses a GROUP BY query instead of loading all devices into memory.
+
+  ## Examples
+
+      iex> get_device_status_counts(organization_id)
+      %{up: 5, down: 2, unknown: 1}
+
+      iex> get_device_status_counts(empty_org_id)
+      %{}
+  """
+  @spec get_device_status_counts(String.t()) :: %{atom() => non_neg_integer()}
+  def get_device_status_counts(organization_id) do
+    from(d in DeviceSchema,
+      where: d.organization_id == ^organization_id,
+      group_by: d.status,
+      select: {d.status, count(d.id)}
+    )
+    |> Repo.all()
+    |> Map.new()
+  end
+
   @doc """
   Returns the list of all devices with monitoring enabled.
   """
diff --git a/lib/towerops/snmp.ex b/lib/towerops/snmp.ex
index eaff81d8..e523e67c 100644
--- a/lib/towerops/snmp.ex
+++ b/lib/towerops/snmp.ex
@@ -372,6 +372,28 @@ defmodule Towerops.Snmp do
     |> Repo.insert()
   end
 
+  @doc """
+  Batch inserts multiple sensor readings using `Repo.insert_all/3`.
+
+  Accepts a list of attribute maps with the same keys as `create_sensor_reading/1`.
+  Generates UUIDs and timestamps automatically. Returns `{count, nil}`.
+  """
+  @spec create_sensor_readings_batch([map()]) :: {non_neg_integer(), nil}
+  def create_sensor_readings_batch([]), do: {0, nil}
+
+  def create_sensor_readings_batch(entries) when is_list(entries) do
+    now = DateTime.truncate(DateTime.utc_now(), :second)
+
+    rows =
+      Enum.map(entries, fn entry ->
+        entry
+        |> Map.put(:id, Ecto.UUID.generate())
+        |> Map.put(:inserted_at, now)
+      end)
+
+    Repo.insert_all(SensorReading, rows)
+  end
+
   @doc """
   Records a new interface stat.
   """
@@ -381,6 +403,28 @@ defmodule Towerops.Snmp do
     |> Repo.insert()
   end
 
+  @doc """
+  Batch inserts multiple interface stats using `Repo.insert_all/3`.
+
+  Accepts a list of attribute maps with the same keys as `create_interface_stat/1`.
+  Generates UUIDs and timestamps automatically. Returns `{count, nil}`.
+  """
+  @spec create_interface_stats_batch([map()]) :: {non_neg_integer(), nil}
+  def create_interface_stats_batch([]), do: {0, nil}
+
+  def create_interface_stats_batch(entries) when is_list(entries) do
+    now = DateTime.truncate(DateTime.utc_now(), :second)
+
+    rows =
+      Enum.map(entries, fn entry ->
+        entry
+        |> Map.put(:id, Ecto.UUID.generate())
+        |> Map.put(:inserted_at, now)
+      end)
+
+    Repo.insert_all(InterfaceStat, rows)
+  end
+
   # Neighbor queries
 
   @doc """
@@ -1383,6 +1427,28 @@ defmodule Towerops.Snmp do
     |> Repo.insert()
   end
 
+  @doc """
+  Batch inserts multiple processor readings using `Repo.insert_all/3`.
+
+  Accepts a list of attribute maps with the same keys as `create_processor_reading/1`.
+  Generates UUIDs and timestamps automatically. Returns `{count, nil}`.
+  """
+  @spec create_processor_readings_batch([map()]) :: {non_neg_integer(), nil}
+  def create_processor_readings_batch([]), do: {0, nil}
+
+  def create_processor_readings_batch(entries) when is_list(entries) do
+    now = DateTime.truncate(DateTime.utc_now(), :second)
+
+    rows =
+      Enum.map(entries, fn entry ->
+        entry
+        |> Map.put(:id, Ecto.UUID.generate())
+        |> Map.put(:inserted_at, now)
+      end)
+
+    Repo.insert_all(ProcessorReading, rows)
+  end
+
   # Storage queries
 
   @doc """
@@ -1490,6 +1556,28 @@ defmodule Towerops.Snmp do
     |> Repo.insert()
   end
 
+  @doc """
+  Batch inserts multiple storage readings using `Repo.insert_all/3`.
+
+  Accepts a list of attribute maps with the same keys as `create_storage_reading/1`.
+  Generates UUIDs and timestamps automatically. Returns `{count, nil}`.
+  """
+  @spec create_storage_readings_batch([map()]) :: {non_neg_integer(), nil}
+  def create_storage_readings_batch([]), do: {0, nil}
+
+  def create_storage_readings_batch(entries) when is_list(entries) do
+    now = DateTime.truncate(DateTime.utc_now(), :second)
+
+    rows =
+      Enum.map(entries, fn entry ->
+        entry
+        |> Map.put(:id, Ecto.UUID.generate())
+        |> Map.put(:inserted_at, now)
+      end)
+
+    Repo.insert_all(StorageReading, rows)
+  end
+
   # ARP Entry queries
 
   @doc """
diff --git a/lib/towerops/workers/device_poller_worker.ex b/lib/towerops/workers/device_poller_worker.ex
index 2a9faf04..28f22496 100644
--- a/lib/towerops/workers/device_poller_worker.ex
+++ b/lib/towerops/workers/device_poller_worker.ex
@@ -413,17 +413,54 @@ defmodule Towerops.Workers.DevicePollerWorker do
   # (These remain unchanged - I'll include them all below)
 
   defp poll_storage(storage_entries, client_opts, timestamp) do
-    storage_entries
-    |> Task.async_stream(
-      fn storage ->
-        result = poll_storage_value(storage, client_opts)
-        handle_storage_poll_result(storage, result, timestamp)
-      end,
-      max_concurrency: 2,
-      timeout: 40_000,
-      on_timeout: :kill_task
-    )
-    |> Stream.run()
+    poll_results =
+      storage_entries
+      |> Task.async_stream(
+        fn storage ->
+          result = poll_storage_value(storage, client_opts)
+          {storage, result}
+        end,
+        max_concurrency: 2,
+        timeout: 40_000,
+        on_timeout: :kill_task
+      )
+      |> Enum.flat_map(fn
+        {:ok, pair} -> [pair]
+        {:exit, _reason} -> []
+      end)
+
+    # Build batch reading entries (only for successful polls)
+    reading_entries =
+      Enum.flat_map(poll_results, fn
+        {storage, {:ok, values}} ->
+          [
+            %{
+              storage_id: storage.id,
+              used_bytes: values.used_bytes,
+              total_bytes: values.total_bytes,
+              usage_percent: values.usage_percent,
+              checked_at: timestamp
+            }
+          ]
+
+        {_storage, {:error, _reason}} ->
+          []
+      end)
+
+    Snmp.create_storage_readings_batch(reading_entries)
+
+    # Process metadata updates individually
+    Enum.each(poll_results, fn
+      {storage, {:ok, values}} ->
+        Snmp.update_storage(storage, %{
+          used_bytes: values.used_bytes,
+          total_bytes: values.total_bytes,
+          last_checked_at: timestamp
+        })
+
+      {storage, {:error, reason}} ->
+        Logger.debug("Failed to poll storage #{storage.description}: #{inspect(reason)}")
+    end)
   end
 
   defp poll_storage_value(storage, client_opts) do
@@ -447,38 +484,35 @@ defmodule Towerops.Workers.DevicePollerWorker do
     end
   end
 
-  defp handle_storage_poll_result(storage, {:ok, values}, timestamp) do
-    Snmp.create_storage_reading(%{
-      storage_id: storage.id,
-      used_bytes: values.used_bytes,
-      total_bytes: values.total_bytes,
-      usage_percent: values.usage_percent,
-      checked_at: timestamp
-    })
-
-    Snmp.update_storage(storage, %{
-      used_bytes: values.used_bytes,
-      total_bytes: values.total_bytes,
-      last_checked_at: timestamp
-    })
-  end
-
-  defp handle_storage_poll_result(storage, {:error, reason}, _timestamp) do
-    Logger.debug("Failed to poll storage #{storage.description}: #{inspect(reason)}")
-  end
-
   defp poll_processors(processors, client_opts, timestamp) do
-    processors
-    |> Task.async_stream(
-      fn processor ->
-        result = poll_processor_value(processor, client_opts)
-        handle_processor_poll_result(processor, result, timestamp)
-      end,
-      max_concurrency: 2,
-      timeout: 40_000,
-      on_timeout: :kill_task
-    )
-    |> Stream.run()
+    poll_results =
+      processors
+      |> Task.async_stream(
+        fn processor ->
+          result = poll_processor_value(processor, client_opts)
+          {processor, result}
+        end,
+        max_concurrency: 2,
+        timeout: 40_000,
+        on_timeout: :kill_task
+      )
+      |> Enum.flat_map(fn
+        {:ok, pair} -> [pair]
+        {:exit, _reason} -> []
+      end)
+
+    # Build batch reading entries
+    reading_entries =
+      Enum.map(poll_results, fn {processor, result} ->
+        build_processor_reading_entry(processor, result, timestamp)
+      end)
+
+    Snmp.create_processor_readings_batch(reading_entries)
+
+    # Process metadata updates individually
+    Enum.each(poll_results, fn {processor, result} ->
+      handle_processor_poll_metadata(processor, result, timestamp)
+    end)
   end
 
   defp poll_processor_value(processor, client_opts) do
@@ -533,46 +567,69 @@ defmodule Towerops.Workers.DevicePollerWorker do
     end
   end
 
-  defp handle_processor_poll_result(processor, {:ok, load_percent}, timestamp) do
-    Snmp.create_processor_reading(%{
+  defp build_processor_reading_entry(processor, {:ok, load_percent}, timestamp) do
+    %{
       processor_id: processor.id,
       load_percent: load_percent,
       status: "ok",
       checked_at: timestamp
-    })
+    }
+  end
 
+  defp build_processor_reading_entry(processor, {:error, reason}, timestamp) do
+    Logger.debug("Failed to poll processor #{processor.description}: #{inspect(reason)}")
+
+    %{
+      processor_id: processor.id,
+      load_percent: nil,
+      status: "error",
+      checked_at: timestamp
+    }
+  end
+
+  defp handle_processor_poll_metadata(processor, {:ok, load_percent}, timestamp) do
     Snmp.update_processor(processor, %{
       load_percent: load_percent,
       last_checked_at: timestamp
     })
   end
 
-  defp handle_processor_poll_result(processor, {:error, reason}, timestamp) do
-    Logger.debug("Failed to poll processor #{processor.description}: #{inspect(reason)}")
-
-    Snmp.create_processor_reading(%{
-      processor_id: processor.id,
-      load_percent: nil,
-      status: "error",
-      checked_at: timestamp
-    })
-  end
+  defp handle_processor_poll_metadata(_processor, {:error, _reason}, _timestamp), do: :ok
 
   defp poll_sensors(sensors, client_opts, timestamp) do
-    sensors
-    |> Task.async_stream(
-      fn sensor ->
-        result = poll_sensor_value(sensor, client_opts)
-        handle_sensor_poll_result(sensor, result, timestamp)
-        sensor.sensor_descr
-      end,
-      max_concurrency: 2,
-      timeout: 40_000,
-      on_timeout: :kill_task
-    )
-    |> Enum.each(fn
-      {:ok, _} -> :ok
-      {:exit, reason} -> Logger.warning("Sensor poll task failed: #{inspect(reason)}")
+    # Poll all sensors concurrently and collect results
+    poll_results =
+      sensors
+      |> Task.async_stream(
+        fn sensor ->
+          result = poll_sensor_value(sensor, client_opts)
+          {sensor, result}
+        end,
+        max_concurrency: 2,
+        timeout: 40_000,
+        on_timeout: :kill_task
+      )
+      |> Enum.flat_map(fn
+        {:ok, pair} ->
+          [pair]
+
+        {:exit, reason} ->
+          Logger.warning("Sensor poll task failed: #{inspect(reason)}")
+          []
+      end)
+
+    # Build batch reading entries
+    reading_entries =
+      Enum.map(poll_results, fn {sensor, result} ->
+        build_sensor_reading_entry(sensor, result, timestamp)
+      end)
+
+    # Batch insert all sensor readings
+    Snmp.create_sensor_readings_batch(reading_entries)
+
+    # Process metadata updates and change detection individually
+    Enum.each(poll_results, fn {sensor, result} ->
+      handle_sensor_poll_metadata(sensor, result, timestamp)
     end)
   end
 
@@ -720,18 +777,43 @@ defmodule Towerops.Workers.DevicePollerWorker do
     end
   end
 
-  defp handle_sensor_poll_result(sensor, {:ok, value}, timestamp) do
-    # For state sensors, map numeric value to state description
+  # Build a reading entry map for batch insert, or nil if not applicable
+  defp build_sensor_reading_entry(sensor, {:ok, value}, timestamp) do
     state_descr = get_state_description(sensor, value)
 
-    Snmp.create_sensor_reading(%{
+    %{
       sensor_id: sensor.id,
       value: value,
       status: "ok",
       state_descr: state_descr,
       checked_at: timestamp
-    })
+    }
+  end
 
+  defp build_sensor_reading_entry(sensor, {:error, :non_numeric}, timestamp) do
+    Logger.debug("Non-numeric SNMP value for sensor #{sensor.sensor_descr}")
+
+    %{
+      sensor_id: sensor.id,
+      value: nil,
+      status: "unknown",
+      checked_at: timestamp
+    }
+  end
+
+  defp build_sensor_reading_entry(sensor, {:error, reason}, timestamp) do
+    log_sensor_error(sensor, reason)
+
+    %{
+      sensor_id: sensor.id,
+      value: nil,
+      status: "error",
+      checked_at: timestamp
+    }
+  end
+
+  # Process metadata updates and change detection (must remain per-sensor)
+  defp handle_sensor_poll_metadata(sensor, {:ok, value}, timestamp) do
     SensorChangeDetector.detect_and_broadcast(sensor, value, timestamp)
 
     Snmp.update_sensor(sensor, %{
@@ -740,27 +822,7 @@ defmodule Towerops.Workers.DevicePollerWorker do
     })
   end
 
-  defp handle_sensor_poll_result(sensor, {:error, :non_numeric}, timestamp) do
-    Logger.debug("Non-numeric SNMP value for sensor #{sensor.sensor_descr}")
-
-    Snmp.create_sensor_reading(%{
-      sensor_id: sensor.id,
-      value: nil,
-      status: "unknown",
-      checked_at: timestamp
-    })
-  end
-
-  defp handle_sensor_poll_result(sensor, {:error, reason}, timestamp) do
-    log_sensor_error(sensor, reason)
-
-    Snmp.create_sensor_reading(%{
-      sensor_id: sensor.id,
-      value: nil,
-      status: "error",
-      checked_at: timestamp
-    })
-  end
+  defp handle_sensor_poll_metadata(_sensor, {:error, _reason}, _timestamp), do: :ok
 
   # Get state description for state sensors from metadata
   defp get_state_description(sensor, value) do
@@ -838,24 +900,27 @@ defmodule Towerops.Workers.DevicePollerWorker do
   end
 
   defp poll_interfaces(interfaces, client_opts, timestamp) do
-    interfaces
-    |> Task.async_stream(
-      fn interface ->
-        {:ok, stat_data} = get_interface_stats(client_opts, interface.if_index)
+    entries =
+      interfaces
+      |> Task.async_stream(
+        fn interface ->
+          {:ok, stat_data} = get_interface_stats(client_opts, interface.if_index)
 
-        stats =
           Map.merge(stat_data, %{
             interface_id: interface.id,
             checked_at: timestamp
           })
+        end,
+        max_concurrency: 2,
+        timeout: 40_000,
+        on_timeout: :kill_task
+      )
+      |> Enum.flat_map(fn
+        {:ok, entry} -> [entry]
+        {:exit, _reason} -> []
+      end)
 
-        Snmp.create_interface_stat(stats)
-      end,
-      max_concurrency: 2,
-      timeout: 40_000,
-      on_timeout: :kill_task
-    )
-    |> Stream.run()
+    Snmp.create_interface_stats_batch(entries)
   end
 
   defp check_interface_changes(interfaces, device, client_opts, timestamp) do
diff --git a/lib/towerops_web/channels/agent_channel.ex b/lib/towerops_web/channels/agent_channel.ex
index ef4dc2a1..f0339e16 100644
--- a/lib/towerops_web/channels/agent_channel.ex
+++ b/lib/towerops_web/channels/agent_channel.ex
@@ -1422,17 +1422,17 @@ defmodule ToweropsWeb.AgentChannel do
     snmp_device = device.snmp_device
     oid_values = normalize_oid_keys(result.oid_values)
     # Use server time to avoid clock drift issues between agents
-    timestamp = DateTime.utc_now()
+    timestamp = DateTime.truncate(DateTime.utc_now(), :second)
 
     Logger.info(
       "Processing polling result for #{device.name}: #{map_size(oid_values)} OIDs, #{length(snmp_device.sensors)} sensors, #{length(snmp_device.interfaces)} interfaces"
     )
 
-    # Process sensor readings (quick path - already in memory)
-    Enum.each(snmp_device.sensors, &process_sensor_reading(&1, oid_values, timestamp))
+    # Batch insert sensor readings and process metadata updates
+    process_sensor_readings_batch(snmp_device.sensors, oid_values, timestamp)
 
-    # Process interface stats (quick path - already in memory)
-    Enum.each(device.snmp_device.interfaces, &process_interface_stats(&1, oid_values, timestamp))
+    # Batch insert interface stats
+    process_interface_stats_batch(snmp_device.interfaces, oid_values, timestamp)
 
     # Process complex SNMP data (neighbors, ARP, MAC, IP addresses, processors, storage)
     # using Replay adapter to reuse existing parsing logic
@@ -1576,47 +1576,69 @@ defmodule ToweropsWeb.AgentChannel do
     end
   end
 
-  defp process_sensor_reading(sensor, oid_values, timestamp) do
+  defp process_sensor_readings_batch(sensors, oid_values, timestamp) do
+    # Build reading entries and collect sensor updates in one pass
+    {reading_entries, sensor_updates} =
+      Enum.reduce(sensors, {[], []}, fn sensor, {readings, updates} ->
+        case resolve_sensor_value(sensor, oid_values) do
+          nil ->
+            {readings, updates}
+
+          final_value ->
+            reading = %{
+              sensor_id: sensor.id,
+              value: final_value,
+              status: "ok",
+              checked_at: timestamp
+            }
+
+            {[reading | readings], [{sensor, final_value} | updates]}
+        end
+      end)
+
+    # Batch insert all sensor readings in one SQL statement
+    Snmp.create_sensor_readings_batch(reading_entries)
+
+    # Process change detection and metadata updates individually
+    Enum.each(sensor_updates, fn {sensor, final_value} ->
+      SensorChangeDetector.detect_and_broadcast(sensor, final_value, timestamp)
+
+      Snmp.update_sensor(sensor, %{
+        last_value: final_value,
+        last_checked_at: timestamp
+      })
+    end)
+  end
+
+  defp resolve_sensor_value(sensor, oid_values) do
     normalized_oid = String.trim_leading(sensor.sensor_oid, ".")
 
-    case Map.get(oid_values, normalized_oid) do
-      nil ->
-        :ok
-
-      value ->
-        with parsed_value when not is_nil(parsed_value) <- parse_float(value) do
-          final_value = Float.round(parsed_value / sensor.sensor_divisor, 1)
-
-          Snmp.create_sensor_reading(%{
-            sensor_id: sensor.id,
-            value: final_value,
-            status: "ok",
-            checked_at: timestamp
-          })
-
-          SensorChangeDetector.detect_and_broadcast(sensor, final_value, timestamp)
-
-          Snmp.update_sensor(sensor, %{
-            last_value: final_value,
-            last_checked_at: timestamp
-          })
-        end
+    with value when not is_nil(value) <- Map.get(oid_values, normalized_oid),
+         parsed when not is_nil(parsed) <- parse_float(value) do
+      Float.round(parsed / sensor.sensor_divisor, 1)
+    else
+      _ -> nil
     end
   end
 
-  defp process_interface_stats(iface, oid_values, timestamp) do
-    idx = iface.if_index
+  defp process_interface_stats_batch(interfaces, oid_values, timestamp) do
+    entries =
+      Enum.map(interfaces, fn iface ->
+        idx = iface.if_index
 
-    Snmp.create_interface_stat(%{
-      interface_id: iface.id,
-      if_in_octets: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.31.1.1.1.6.#{idx}")),
-      if_out_octets: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.31.1.1.1.10.#{idx}")),
-      if_in_errors: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.2.2.1.14.#{idx}")),
-      if_out_errors: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.2.2.1.20.#{idx}")),
-      if_in_discards: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.2.2.1.13.#{idx}")),
-      if_out_discards: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.2.2.1.19.#{idx}")),
-      checked_at: timestamp
-    })
+        %{
+          interface_id: iface.id,
+          if_in_octets: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.31.1.1.1.6.#{idx}")),
+          if_out_octets: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.31.1.1.1.10.#{idx}")),
+          if_in_errors: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.2.2.1.14.#{idx}")),
+          if_out_errors: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.2.2.1.20.#{idx}")),
+          if_in_discards: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.2.2.1.13.#{idx}")),
+          if_out_discards: parse_integer(Map.get(oid_values, "1.3.6.1.2.1.2.2.1.19.#{idx}")),
+          checked_at: timestamp
+        }
+      end)
+
+    Snmp.create_interface_stats_batch(entries)
   end
 
   defp parse_integer(nil), do: nil
diff --git a/lib/towerops_web/live/dashboard_live.ex b/lib/towerops_web/live/dashboard_live.ex
index 4c071edb..8a64c6f6 100644
--- a/lib/towerops_web/live/dashboard_live.ex
+++ b/lib/towerops_web/live/dashboard_live.ex
@@ -36,20 +36,17 @@ defmodule ToweropsWeb.DashboardLive do
   defp load_dashboard_data(socket, organization_id) do
     organization = socket.assigns.current_scope.organization
     active_alerts = Alerts.list_organization_active_alerts(organization_id)
-    sites_count = if organization.use_sites, do: length(Sites.list_organization_sites(organization_id)), else: 0
-    devices = Devices.list_organization_devices(organization_id)
+    sites_count = if organization.use_sites, do: Sites.count_organization_sites(organization_id), else: 0
+    status_counts = Devices.get_device_status_counts(organization_id)
 
-    devices_by_status =
-      devices
-      |> Enum.group_by(& &1.status)
-      |> Map.new(fn {status, equip} -> {status, length(equip)} end)
+    device_count = status_counts |> Map.values() |> Enum.sum()
 
     socket
     |> assign(:active_alerts, active_alerts)
     |> assign(:sites_count, sites_count)
-    |> assign(:device_count, length(devices))
-    |> assign(:device_up, Map.get(devices_by_status, :up, 0))
-    |> assign(:device_down, Map.get(devices_by_status, :down, 0))
-    |> assign(:device_unknown, Map.get(devices_by_status, :unknown, 0))
+    |> assign(:device_count, device_count)
+    |> assign(:device_up, Map.get(status_counts, :up, 0))
+    |> assign(:device_down, Map.get(status_counts, :down, 0))
+    |> assign(:device_unknown, Map.get(status_counts, :unknown, 0))
   end
 end
diff --git a/lib/towerops_web/live/device_live/index.ex b/lib/towerops_web/live/device_live/index.ex
index f30821d9..567f6491 100644
--- a/lib/towerops_web/live/device_live/index.ex
+++ b/lib/towerops_web/live/device_live/index.ex
@@ -31,7 +31,8 @@ defmodule ToweropsWeb.DeviceLive.Index do
      |> assign(:sites_enabled, organization.use_sites)
      |> assign(:has_sites, sites != [])
      |> assign(:reorder_mode, false)
-     |> assign(:device_quota, %{current: current, limit: limit})}
+     |> assign(:device_quota, %{current: current, limit: limit})
+     |> assign(:pending_reload_ref, nil)}
   end
 
   @impl true
@@ -210,12 +211,47 @@ defmodule ToweropsWeb.DeviceLive.Index do
     end
   end
 
+  # Structural changes (create/delete) need full reload with quota recalculation
   @impl true
-  def handle_info({event, _org_id}, socket)
-      when event in [:device_created, :device_updated, :device_deleted, :device_status_changed] do
+  def handle_info({event, _org_id}, socket) when event in [:device_created, :device_deleted] do
     {:noreply, reload_devices(socket)}
   end
 
+  # Status changes and updates are debounced to avoid redundant reloads
+  # when many devices change status simultaneously (e.g., network event)
+  @impl true
+  def handle_info({event, _org_id}, socket) when event in [:device_status_changed, :device_updated] do
+    {:noreply, schedule_debounced_reload(socket, event)}
+  end
+
+  @impl true
+  def handle_info(:debounced_device_reload, socket) do
+    {:noreply, reload_device_stream(socket)}
+  end
+
+  @debounce_ms if Mix.env() == :test, do: 0, else: 100
+
+  defp schedule_debounced_reload(socket, event) do
+    # Cancel any pending debounced reload
+    if ref = socket.assigns.pending_reload_ref do
+      Process.cancel_timer(ref)
+    end
+
+    # For status changes, skip reload entirely if viewing the discovered tab
+    if event == :device_status_changed && socket.assigns.active_tab == "discovered" do
+      assign(socket, :pending_reload_ref, nil)
+    else
+      if @debounce_ms == 0 do
+        # In test: reload immediately so render(view) sees the update
+        reload_device_stream(socket)
+      else
+        ref = Process.send_after(self(), :debounced_device_reload, @debounce_ms)
+        assign(socket, :pending_reload_ref, ref)
+      end
+    end
+  end
+
+  # Full reload: stream + quota (for structural changes like create/delete)
   defp reload_devices(socket) do
     organization = socket.assigns.current_scope.organization
     devices = Devices.list_organization_devices(organization.id)
@@ -227,6 +263,17 @@ defmodule ToweropsWeb.DeviceLive.Index do
     |> assign(:device_quota, %{current: current, limit: limit})
   end
 
+  # Lightweight reload: stream only, skip quota query (for status/update changes)
+  defp reload_device_stream(socket) do
+    organization = socket.assigns.current_scope.organization
+    devices = Devices.list_organization_devices(organization.id)
+
+    socket
+    |> stream(:device_rows, build_device_rows(devices), reset: true)
+    |> assign(:has_devices, devices != [])
+    |> assign(:pending_reload_ref, nil)
+  end
+
   defp enqueue_discovery(device_id) do
     if Application.get_env(:towerops, :env) == :test do
       _ = Task.start(fn -> Snmp.discover_device(Devices.get_device!(device_id)) end)
diff --git a/lib/towerops_web/live/device_live/show.ex b/lib/towerops_web/live/device_live/show.ex
index 25d5058a..32369119 100644
--- a/lib/towerops_web/live/device_live/show.ex
+++ b/lib/towerops_web/live/device_live/show.ex
@@ -96,17 +96,19 @@ defmodule ToweropsWeb.DeviceLive.Show do
 
       _device ->
         Process.send_after(self(), :refresh_data, 10_000)
-        {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+        {:noreply, reload_active_tab_data(socket)}
     end
   end
 
   @impl true
   def handle_info({:device_status_changed, _device_id, _new_status, _response_time}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    # Device status shows on all tabs in the header - reload base data only
+    {:noreply, reload_base_data(socket)}
   end
 
   @impl true
   def handle_info({:discovery_completed, _device_id}, socket) do
+    # Structural change - full reload needed
     {:noreply,
      socket
      |> load_equipment_data(socket.assigns.device.id)
@@ -115,61 +117,60 @@ defmodule ToweropsWeb.DeviceLive.Show do
 
   @impl true
   def handle_info({:sensors_updated, _device_id}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["overview"])}
   end
 
   @impl true
   def handle_info({:interfaces_updated, _device_id}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["overview", "ports"])}
   end
 
   @impl true
   def handle_info({:neighbors_updated, _device_id}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["neighbors"])}
   end
 
   @impl true
   def handle_info({:arp_updated, _device_id}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["arp"])}
   end
 
   @impl true
   def handle_info({:mac_updated, _device_id}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["mac"])}
   end
 
   @impl true
   def handle_info({:state_sensors_updated, _device_id}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["overview"])}
   end
 
   @impl true
   def handle_info({:processors_updated, _device_id}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["overview"])}
   end
 
   @impl true
   def handle_info({:storage_updated, _device_id}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["overview"])}
   end
 
   @impl true
   def handle_info({:monitoring_check_updated, _device_id}, socket) do
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["overview"])}
   end
 
   @impl true
   def handle_info({:device_event, _event_attrs}, socket) do
     # Device event logged (interface changes, sensor thresholds, etc.)
-    # Reload to update events list
-    {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+    {:noreply, reload_if_tab(socket, ["logs"])}
   end
 
   @impl true
   def handle_info({:agent_connected, agent_token_id, _organization_id}, socket) do
-    # Reload if this device's agent just connected
+    # Reload agent info if this device's agent just connected
     if socket.assigns.agent_info.agent_token_id == agent_token_id do
-      {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+      {:noreply, reload_base_data(socket)}
     else
       {:noreply, socket}
     end
@@ -177,9 +178,9 @@ defmodule ToweropsWeb.DeviceLive.Show do
 
   @impl true
   def handle_info({:agent_disconnected, agent_token_id, _organization_id}, socket) do
-    # Reload if this device's agent just disconnected
+    # Reload agent info if this device's agent just disconnected
     if socket.assigns.agent_info.agent_token_id == agent_token_id do
-      {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+      {:noreply, reload_base_data(socket)}
     else
       {:noreply, socket}
     end
@@ -187,9 +188,9 @@ defmodule ToweropsWeb.DeviceLive.Show do
 
   @impl true
   def handle_info({:agent_heartbeat, agent_token_id, _organization_id}, socket) do
-    # Reload if this device's agent sent a heartbeat (important for stale agents coming back)
+    # Reload agent info if this device's agent sent a heartbeat
     if socket.assigns.agent_info.agent_token_id == agent_token_id do
-      {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+      {:noreply, reload_base_data(socket)}
     else
       {:noreply, socket}
     end
@@ -197,11 +198,11 @@ defmodule ToweropsWeb.DeviceLive.Show do
 
   @impl true
   def handle_info({:agents_stale, stale_agents}, socket) do
-    # Reload if this device's agent went stale
+    # Reload agent info if this device's agent went stale
     device_agent_id = socket.assigns.agent_info.agent_token_id
 
     if device_agent_id && Enum.any?(stale_agents, &(&1.id == device_agent_id)) do
-      {:noreply, load_equipment_data(socket, socket.assigns.device.id)}
+      {:noreply, reload_base_data(socket)}
     else
       {:noreply, socket}
     end
@@ -220,21 +221,111 @@ defmodule ToweropsWeb.DeviceLive.Show do
     :ok
   end
 
+  # -- Full data load (initial page load and discovery_completed) --
+
+  # Loads all data for every tab. Called from handle_params (initial load)
+  # and discovery_completed (structural change requiring full refresh).
   defp load_equipment_data(socket, device_id) do
+    socket
+    |> assign_base_data(device_id)
+    |> assign_tab_nav_data(device_id)
+    |> assign_overview_data(device_id)
+    |> assign_ports_data()
+    |> assign_logs_data(device_id)
+    |> assign_backups_data(device_id)
+  end
+
+  # -- Selective reload helpers (used by handle_info handlers) --
+
+  # Reload only base data (device, agent_info, snmp_device).
+  # Used when device status or agent state changes - these show in the header on all tabs.
+  defp reload_base_data(socket) do
+    assign_base_data(socket, socket.assigns.device.id)
+  end
+
+  # Reload base data + data for the currently active tab only.
+  # Used by the periodic refresh timer.
+  defp reload_active_tab_data(socket) do
+    device_id = socket.assigns.device.id
+
+    socket
+    |> assign_base_data(device_id)
+    |> assign_tab_nav_data(device_id)
+    |> reload_current_tab_data(device_id)
+  end
+
+  # Reload data only if the active tab is one of the relevant tabs.
+  # Otherwise does nothing - the event is irrelevant to what the user sees.
+  defp reload_if_tab(socket, relevant_tabs) do
+    if socket.assigns.active_tab in relevant_tabs do
+      reload_current_tab_data(socket, socket.assigns.device.id)
+    else
+      socket
+    end
+  end
+
+  # Dispatch to the appropriate tab-specific loader based on active_tab.
+  defp reload_current_tab_data(socket, device_id) do
+    case socket.assigns.active_tab do
+      "overview" -> assign_overview_data(socket, device_id)
+      "ports" -> assign_ports_data(socket)
+      "logs" -> assign_logs_data(socket, device_id)
+      "backups" -> assign_backups_data(socket, device_id)
+      # neighbors, arp, mac, vlans, ip_addresses, debug use data from tab_nav/base
+      _ -> socket
+    end
+  end
+
+  # -- Focused data loaders --
+
+  # Base data needed by all tabs: device record, agent info, SNMP device/sensors/interfaces.
+  defp assign_base_data(socket, device_id) do
     device = Devices.get_device!(device_id)
     device_with_associations = Repo.preload(device, [:organization, site: [organization: :default_agent_token]])
     {agent_token_id, agent_source} = Agents.get_effective_agent_token_with_source(device_with_associations)
     agent_info = load_agent_info(agent_token_id, agent_source)
-    recent_checks = Monitoring.list_devices_checks(device_id, 50)
     snmp_data = load_snmp_data(device_id)
-    events = Devices.list_devices_events(device_id, 100)
+
+    socket
+    |> assign(:page_title, device.name)
+    |> assign(:timezone, socket.assigns.current_scope.timezone)
+    |> assign(:device, device)
+    |> assign(:agent_info, agent_info)
+    |> assign(:snmp_device, snmp_data.device)
+    |> assign(:snmp_interfaces, snmp_data.interfaces)
+    |> assign(:snmp_sensors, snmp_data.sensors)
+  end
+
+  # Data needed for the tab navigation bar to decide which tabs to show.
+  # Neighbors, ARP, MAC, VLANs, and IP addresses determine tab visibility.
+  defp assign_tab_nav_data(socket, device_id) do
+    snmp_device = socket.assigns.snmp_device
     neighbors = Snmp.list_neighbors_with_equipment(device_id)
     arp_entries = Snmp.list_arp_entries(device_id)
     mac_addresses = Snmp.list_mac_addresses(device_id)
-    vlans = load_vlans(snmp_data.device)
-    ip_addresses = load_ip_addresses(snmp_data.device)
-    processors = load_processors(snmp_data.device)
-    storage = load_storage(snmp_data.device)
+    vlans = load_vlans(snmp_device)
+    ip_addresses = load_ip_addresses(snmp_device)
+
+    socket
+    |> assign(:neighbors, neighbors)
+    |> assign(:arp_entries, arp_entries)
+    |> assign(:mac_addresses, mac_addresses)
+    |> assign(:vlans, vlans)
+    |> assign(:ipv4_addresses, Enum.filter(ip_addresses, &(&1.ip_type == "ipv4")))
+    |> assign(:ipv6_addresses, Enum.filter(ip_addresses, &(&1.ip_type == "ipv6")))
+    |> assign(:ip_addresses_by_interface, group_ip_addresses_by_interface(ip_addresses))
+  end
+
+  # Overview tab: charts, sensor classifications, metrics, processors, storage, firmware.
+  # This is the most expensive loader due to time-series chart data queries.
+  defp assign_overview_data(socket, device_id) do
+    device = socket.assigns.device
+    snmp_device = socket.assigns.snmp_device
+    sensors = socket.assigns.snmp_sensors
+
+    recent_checks = Monitoring.list_devices_checks(device_id, 50)
+    processors = load_processors(snmp_device)
+    storage = load_storage(snmp_device)
     latency_chart_data = load_latency_chart_data(device_id)
     processor_chart_data = load_processor_chart_data(processors)
     memory_chart_data = load_sensor_chart_data(device_id, ["memory_usage"])
@@ -242,7 +333,6 @@ defmodule ToweropsWeb.DeviceLive.Show do
     storage_volume_chart_data = load_storage_volume_chart_data(storage)
     traffic_chart_data = load_overall_traffic_chart_data(device_id)
 
-    # Wireless sensor chart data
     wireless_chart_data =
       load_sensor_chart_data(device_id, [
         "frequency",
@@ -257,81 +347,35 @@ defmodule ToweropsWeb.DeviceLive.Show do
         "utilization"
       ])
 
-    # Filter sensors by type for temperature, voltage, storage, count, and transceivers
-    # Separate transceiver sensors from general sensors
+    # Classify sensors by type
     {transceiver_sensors, non_transceiver_sensors} =
-      Enum.split_with(snmp_data.sensors, fn sensor ->
+      Enum.split_with(sensors, fn sensor ->
         sensor.sensor_descr && String.contains?(String.downcase(sensor.sensor_descr), "sfp")
       end)
 
-    temperature_sensors =
-      Enum.filter(non_transceiver_sensors, &temperature_sensor?/1)
-
+    temperature_sensors = Enum.filter(non_transceiver_sensors, &temperature_sensor?/1)
     voltage_sensors = Enum.filter(non_transceiver_sensors, &voltage_sensor?/1)
-
     current_sensors = Enum.filter(non_transceiver_sensors, &current_sensor?/1)
-
     power_sensors = Enum.filter(non_transceiver_sensors, &power_sensor?/1)
-
     fan_sensors = Enum.filter(non_transceiver_sensors, &fan_sensor?/1)
-
     load_sensors = Enum.filter(non_transceiver_sensors, &load_sensor?/1)
-
     storage_sensors = Enum.filter(non_transceiver_sensors, &(&1.sensor_type in ["disk_usage"]))
-
-    # Include various counter/gauge sensor types in the Counters section
     count_sensors = Enum.filter(non_transceiver_sensors, &counter_sensor?/1)
 
-    # Split count sensors into firewall and general
     {firewall_counters, general_counters} =
       Enum.split_with(count_sensors, &firewall_counter?/1)
 
-    # Wireless sensors (frequency, power, rssi, ccq, etc.)
     wireless_sensors = Enum.filter(non_transceiver_sensors, &wireless_sensor?/1)
-
-    # Signal quality sensors (SNR, RSSI, RSRP, etc.)
     signal_sensors = Enum.filter(non_transceiver_sensors, &signal_sensor?/1)
-
-    # Group transceiver sensors by transceiver name
     grouped_transceivers = group_transceiver_sensors(transceiver_sensors)
-
-    # Calculate metrics for dashboard
     metrics = calculate_metrics(recent_checks, device)
-
-    # Group interfaces by type for the ports tab
-    interfaces_by_type = group_interfaces_by_type(snmp_data.interfaces)
-
-    # Check for available firmware updates
-    available_firmware = get_available_firmware(snmp_data.device)
-
-    # Load MikroTik backups if device has MikroTik API enabled
-    mikrotik_backups =
-      if device.mikrotik_enabled do
-        MikrotikBackups.list_device_backups(device_id, limit: 50)
-      else
-        []
-      end
+    available_firmware = get_available_firmware(snmp_device)
 
     socket
-    |> assign(:page_title, device.name)
-    |> assign(:timezone, socket.assigns.current_scope.timezone)
-    |> assign(:device, device)
     |> assign(:recent_checks, recent_checks)
     |> assign(:metrics, metrics)
-    |> assign(:snmp_device, snmp_data.device)
-    |> assign(:snmp_interfaces, snmp_data.interfaces)
-    |> assign(:interfaces_by_type, interfaces_by_type)
-    |> assign(:snmp_sensors, snmp_data.sensors)
-    |> assign(:neighbors, neighbors)
-    |> assign(:arp_entries, arp_entries)
-    |> assign(:mac_addresses, mac_addresses)
-    |> assign(:vlans, vlans)
-    |> assign(:ipv4_addresses, Enum.filter(ip_addresses, &(&1.ip_type == "ipv4")))
-    |> assign(:ipv6_addresses, Enum.filter(ip_addresses, &(&1.ip_type == "ipv6")))
-    |> assign(:ip_addresses_by_interface, group_ip_addresses_by_interface(ip_addresses))
     |> assign(:processors, processors)
     |> assign(:storage, storage)
-    |> assign(:events, events)
     |> assign(:latency_chart_data, latency_chart_data)
     |> assign(:processor_chart_data, processor_chart_data)
     |> assign(:memory_chart_data, memory_chart_data)
@@ -352,8 +396,36 @@ defmodule ToweropsWeb.DeviceLive.Show do
     |> assign(:wireless_sensors, wireless_sensors)
     |> assign(:signal_sensors, signal_sensors)
     |> assign(:grouped_transceivers, grouped_transceivers)
-    |> assign(:agent_info, agent_info)
     |> assign(:available_firmware, available_firmware)
+  end
+
+  # Ports tab: interfaces grouped by type.
+  # Uses snmp_interfaces already loaded in base data.
+  defp assign_ports_data(socket) do
+    interfaces = socket.assigns.snmp_interfaces
+    interfaces_by_type = group_interfaces_by_type(interfaces)
+
+    assign(socket, :interfaces_by_type, interfaces_by_type)
+  end
+
+  # Logs/events tab data.
+  defp assign_logs_data(socket, device_id) do
+    events = Devices.list_devices_events(device_id, 100)
+    assign(socket, :events, events)
+  end
+
+  # Backups tab data.
+  defp assign_backups_data(socket, device_id) do
+    device = socket.assigns.device
+
+    mikrotik_backups =
+      if device.mikrotik_enabled do
+        MikrotikBackups.list_device_backups(device_id, limit: 50)
+      else
+        []
+      end
+
+    socket
     |> assign(:mikrotik_backups, mikrotik_backups)
     |> assign(:selected_backup_ids, MapSet.new())
   end
diff --git a/priv/repo/migrations/20260212155105_add_performance_indexes.exs b/priv/repo/migrations/20260212155105_add_performance_indexes.exs
new file mode 100644
index 00000000..77febe4d
--- /dev/null
+++ b/priv/repo/migrations/20260212155105_add_performance_indexes.exs
@@ -0,0 +1,39 @@
+defmodule Towerops.Repo.Migrations.AddPerformanceIndexes do
+  use Ecto.Migration
+
+  @disable_ddl_transaction true
+  @disable_migration_lock true
+
+  def change do
+    # Partial index for monitored sensors (WHERE monitored = true)
+    # Used by Snmp.list_monitored_sensors/1
+    create index(:snmp_sensors, [:monitored],
+             where: "monitored = true",
+             name: :snmp_sensors_monitored_true_idx,
+             concurrently: true
+           )
+
+    # Partial index for monitored interfaces (WHERE monitored = true)
+    # Used by Snmp.list_monitored_interfaces/1
+    create index(:snmp_interfaces, [:monitored],
+             where: "monitored = true",
+             name: :snmp_interfaces_monitored_true_idx,
+             concurrently: true
+           )
+
+    # Composite index for devices filtered by org + status
+    # Used by Devices.list_organization_devices/2 with status filter
+    create index(:devices, [:organization_id, :status],
+             name: :devices_organization_id_status_idx,
+             concurrently: true
+           )
+
+    # Partial index for active (unresolved) alerts
+    # Used by Alerts.list_organization_active_alerts/1
+    create index(:alerts, [:resolved_at],
+             where: "resolved_at IS NULL",
+             name: :alerts_active_idx,
+             concurrently: true
+           )
+  end
+end
diff --git a/test/towerops/devices/device_status_counts_test.exs b/test/towerops/devices/device_status_counts_test.exs
new file mode 100644
index 00000000..7cbc93da
--- /dev/null
+++ b/test/towerops/devices/device_status_counts_test.exs
@@ -0,0 +1,129 @@
+defmodule Towerops.Devices.DeviceStatusCountsTest do
+  use Towerops.DataCase, async: true
+
+  import Towerops.AccountsFixtures
+
+  alias Towerops.Devices
+
+  setup do
+    user = user_fixture()
+    {:ok, organization} = Towerops.Organizations.create_organization(%{name: "Test Org"}, user.id)
+
+    {:ok, site} =
+      Towerops.Sites.create_site(%{
+        name: "Test Site",
+        organization_id: organization.id
+      })
+
+    %{organization: organization, site: site}
+  end
+
+  describe "get_device_status_counts/1" do
+    test "returns empty map when no devices exist", %{organization: organization} do
+      assert Devices.get_device_status_counts(organization.id) == %{}
+    end
+
+    test "returns correct counts for mixed statuses", %{organization: organization, site: site} do
+      # Create devices and set their statuses
+      for i <- 1..3 do
+        {:ok, device} =
+          Devices.create_device(%{
+            name: "Up Device #{i}",
+            ip_address: "192.168.1.#{i}",
+            site_id: site.id,
+            organization_id: organization.id
+          })
+
+        Devices.update_device_status(device, :up)
+      end
+
+      for i <- 1..2 do
+        {:ok, device} =
+          Devices.create_device(%{
+            name: "Down Device #{i}",
+            ip_address: "192.168.2.#{i}",
+            site_id: site.id,
+            organization_id: organization.id
+          })
+
+        Devices.update_device_status(device, :down)
+      end
+
+      {:ok, _unknown_device} =
+        Devices.create_device(%{
+          name: "Unknown Device",
+          ip_address: "192.168.3.1",
+          site_id: site.id,
+          organization_id: organization.id
+        })
+
+      # Unknown is the default status, so no need to update
+
+      counts = Devices.get_device_status_counts(organization.id)
+
+      assert counts == %{up: 3, down: 2, unknown: 1}
+    end
+
+    test "only counts devices for the given organization", %{organization: organization, site: site} do
+      # Create device in our org
+      {:ok, device} =
+        Devices.create_device(%{
+          name: "Our Device",
+          ip_address: "192.168.1.1",
+          site_id: site.id,
+          organization_id: organization.id
+        })
+
+      Devices.update_device_status(device, :up)
+
+      # Create device in a different org
+      other_user = user_fixture()
+      {:ok, other_org} = Towerops.Organizations.create_organization(%{name: "Other Org"}, other_user.id)
+
+      {:ok, other_site} =
+        Towerops.Sites.create_site(%{
+          name: "Other Site",
+          organization_id: other_org.id
+        })
+
+      {:ok, other_device} =
+        Devices.create_device(%{
+          name: "Other Device",
+          ip_address: "192.168.1.1",
+          site_id: other_site.id,
+          organization_id: other_org.id
+        })
+
+      Devices.update_device_status(other_device, :down)
+
+      # Our org should only see its own device
+      counts = Devices.get_device_status_counts(organization.id)
+      assert counts == %{up: 1}
+
+      # Other org should only see its own device
+      other_counts = Devices.get_device_status_counts(other_org.id)
+      assert other_counts == %{down: 1}
+    end
+
+    test "returns correct counts after status changes", %{organization: organization, site: site} do
+      {:ok, device} =
+        Devices.create_device(%{
+          name: "Device",
+          ip_address: "192.168.1.1",
+          site_id: site.id,
+          organization_id: organization.id
+        })
+
+      # Initially unknown
+      assert Devices.get_device_status_counts(organization.id) == %{unknown: 1}
+
+      # Change to up
+      {:ok, device} = Devices.update_device_status(device, :up)
+      assert Devices.get_device_status_counts(organization.id) == %{up: 1}
+
+      # Change to down
+      {:ok, _device} = Devices.update_device_status(device, :down)
+      assert Devices.get_device_status_counts(organization.id) == %{down: 1}
+    end
+  end
+end
diff --git a/test/towerops/snmp/batch_insert_test.exs b/test/towerops/snmp/batch_insert_test.exs
new file mode 100644
index 00000000..335d5e3b
--- /dev/null
+++ b/test/towerops/snmp/batch_insert_test.exs
@@ -0,0 +1,459 @@
+defmodule Towerops.Snmp.BatchInsertTest do
+  use Towerops.DataCase, async: true
+
+  import Towerops.AccountsFixtures
+
+  alias Towerops.Repo
+  alias Towerops.Snmp
+  alias Towerops.Snmp.Device
+  alias Towerops.Snmp.Interface
+  alias Towerops.Snmp.InterfaceStat
+  alias Towerops.Snmp.Processor
+  alias Towerops.Snmp.ProcessorReading
+  alias Towerops.Snmp.Sensor
+  alias Towerops.Snmp.SensorReading
+  alias Towerops.Snmp.Storage
+  alias Towerops.Snmp.StorageReading
+
+  setup do
+    user = user_fixture()
+    {:ok, organization} = Towerops.Organizations.create_organization(%{name: "Test Org"}, user.id)
+
+    {:ok, site} =
+      Towerops.Sites.create_site(%{
+        name: "Test Site",
+        organization_id: organization.id
+      })
+
+    {:ok, device} =
+      Towerops.Devices.create_device(%{
+        name: "Test Router",
+        ip_address: "192.168.1.1",
+        snmp_enabled: true,
+        snmp_version: "2c",
+        snmp_community: "public",
+        snmp_port: 161,
+        site_id: site.id,
+        organization_id: organization.id
+      })
+
+    snmp_device =
+      %Device{}
+      |> Device.changeset(%{
+        device_id: device.id,
+        sys_name: "test-router",
+        sys_descr: "Test Device"
+      })
+      |> Repo.insert!()
+
+    sensor =
+      %Sensor{}
+      |> Sensor.changeset(%{
+        snmp_device_id: snmp_device.id,
+        sensor_type: "temperature",
+        sensor_index: "temp_1",
+        sensor_oid: "1.3.6.1.4.1.9.9.91.1.1.1.1.4.1"
+      })
+      |> Repo.insert!()
+
+    sensor2 =
+      %Sensor{}
+      |> Sensor.changeset(%{
+        snmp_device_id: snmp_device.id,
+        sensor_type: "voltage",
+        sensor_index: "volt_1",
+        sensor_oid: "1.3.6.1.4.1.9.9.91.1.1.1.1.4.2"
+      })
+      |> Repo.insert!()
+
+    interface =
+      %Interface{}
+      |> Interface.changeset(%{
+        snmp_device_id: snmp_device.id,
+        if_index: 1,
+        if_name: "eth0"
+      })
+      |> Repo.insert!()
+
+    interface2 =
+      %Interface{}
+      |> Interface.changeset(%{
+        snmp_device_id: snmp_device.id,
+        if_index: 2,
+        if_name: "eth1"
+      })
+      |> Repo.insert!()
+
+    processor =
+      %Processor{}
+      |> Processor.changeset(%{
+        snmp_device_id: snmp_device.id,
+        processor_index: "1",
+        processor_type: "hr_processor",
+        description: "CPU 1"
+      })
+      |> Repo.insert!()
+
+    processor2 =
+      %Processor{}
+      |> Processor.changeset(%{
+        snmp_device_id: snmp_device.id,
+        processor_index: "2",
+        processor_type: "hr_processor",
+        description: "CPU 2"
+      })
+      |> Repo.insert!()
+
+    storage =
+      %Storage{}
+      |> Storage.changeset(%{
+        snmp_device_id: snmp_device.id,
+        storage_index: 1,
+        storage_type: "fixed_disk",
+        description: "/dev/sda1"
+      })
+      |> Repo.insert!()
+
+    storage2 =
+      %Storage{}
+      |> Storage.changeset(%{
+        snmp_device_id: snmp_device.id,
+        storage_index: 2,
+        storage_type: "ram",
+        description: "Physical Memory"
+      })
+      |> Repo.insert!()
+
+    %{
+      snmp_device: snmp_device,
+      sensor: sensor,
+      sensor2: sensor2,
+      interface: interface,
+      interface2: interface2,
+      processor: processor,
+      processor2: processor2,
+      storage: storage,
+      storage2: storage2
+    }
+  end
+
+  describe "create_sensor_readings_batch/1" do
+    test "inserts multiple sensor readings", %{sensor: sensor, sensor2: sensor2} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{sensor_id: sensor.id, value: 25.5, status: "ok", checked_at: now},
+        %{sensor_id: sensor2.id, value: 3.3, status: "warning", checked_at: now}
+      ]
+
+      assert {2, nil} = Snmp.create_sensor_readings_batch(entries)
+
+      readings = Repo.all(SensorReading)
+      assert length(readings) == 2
+
+      reading1 = Enum.find(readings, &(&1.sensor_id == sensor.id))
+      assert reading1.value == 25.5
+      assert reading1.status == "ok"
+      assert reading1.checked_at == now
+      assert reading1.id
+      assert reading1.inserted_at
+
+      reading2 = Enum.find(readings, &(&1.sensor_id == sensor2.id))
+      assert reading2.value == 3.3
+      assert reading2.status == "warning"
+    end
+
+    test "returns {0, nil} for empty list" do
+      assert {0, nil} = Snmp.create_sensor_readings_batch([])
+      assert Repo.all(SensorReading) == []
+    end
+
+    test "generates unique UUIDs for each entry", %{sensor: sensor} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{sensor_id: sensor.id, value: 10.0, status: "ok", checked_at: now},
+        %{sensor_id: sensor.id, value: 11.0, status: "ok", checked_at: now}
+      ]
+
+      {2, nil} = Snmp.create_sensor_readings_batch(entries)
+
+      readings = Repo.all(SensorReading)
+      ids = Enum.map(readings, & &1.id)
+      assert length(Enum.uniq(ids)) == 2
+    end
+
+    test "handles optional state_descr field", %{sensor: sensor} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{
+          sensor_id: sensor.id,
+          value: 25.5,
+          status: "ok",
+          state_descr: "Normal operating temperature",
+          checked_at: now
+        }
+      ]
+
+      assert {1, nil} = Snmp.create_sensor_readings_batch(entries)
+
+      [reading] = Repo.all(SensorReading)
+      assert reading.state_descr == "Normal operating temperature"
+    end
+
+    test "handles entries with nil value", %{sensor: sensor} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{sensor_id: sensor.id, value: nil, status: "error", checked_at: now}
+      ]
+
+      assert {1, nil} = Snmp.create_sensor_readings_batch(entries)
+
+      [reading] = Repo.all(SensorReading)
+      assert reading.value == nil
+      assert reading.status == "error"
+    end
+  end
+
+  describe "create_interface_stats_batch/1" do
+    test "inserts multiple interface stats", %{interface: interface, interface2: interface2} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{
+          interface_id: interface.id,
+          if_in_octets: 1000,
+          if_out_octets: 2000,
+          if_in_errors: 0,
+          if_out_errors: 0,
+          if_in_discards: 0,
+          if_out_discards: 0,
+          checked_at: now
+        },
+        %{
+          interface_id: interface2.id,
+          if_in_octets: 5000,
+          if_out_octets: 6000,
+          if_in_errors: 1,
+          if_out_errors: 2,
+          if_in_discards: 3,
+          if_out_discards: 4,
+          checked_at: now
+        }
+      ]
+
+      assert {2, nil} = Snmp.create_interface_stats_batch(entries)
+
+      stats = Repo.all(InterfaceStat)
+      assert length(stats) == 2
+
+      stat1 = Enum.find(stats, &(&1.interface_id == interface.id))
+      assert stat1.if_in_octets == 1000
+      assert stat1.if_out_octets == 2000
+      assert stat1.if_in_errors == 0
+      assert stat1.if_out_errors == 0
+      assert stat1.if_in_discards == 0
+      assert stat1.if_out_discards == 0
+      assert stat1.checked_at == now
+      assert stat1.id
+      assert stat1.inserted_at
+
+      stat2 = Enum.find(stats, &(&1.interface_id == interface2.id))
+      assert stat2.if_in_octets == 5000
+      assert stat2.if_out_octets == 6000
+      assert stat2.if_in_errors == 1
+      assert stat2.if_out_errors == 2
+    end
+
+    test "returns {0, nil} for empty list" do
+      assert {0, nil} = Snmp.create_interface_stats_batch([])
+      assert Repo.all(InterfaceStat) == []
+    end
+
+    test "generates unique UUIDs for each entry", %{interface: interface} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{interface_id: interface.id, if_in_octets: 100, if_out_octets: 200, checked_at: now},
+        %{interface_id: interface.id, if_in_octets: 300, if_out_octets: 400, checked_at: now}
+      ]
+
+      {2, nil} = Snmp.create_interface_stats_batch(entries)
+
+      stats = Repo.all(InterfaceStat)
+      ids = Enum.map(stats, & &1.id)
+      assert length(Enum.uniq(ids)) == 2
+    end
+
+    test "handles entries with nil counter values", %{interface: interface} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{interface_id: interface.id, if_in_octets: nil, if_out_octets: nil, checked_at: now}
+      ]
+
+      assert {1, nil} = Snmp.create_interface_stats_batch(entries)
+
+      [stat] = Repo.all(InterfaceStat)
+      assert stat.if_in_octets == nil
+      assert stat.if_out_octets == nil
+    end
+  end
+
+  describe "create_processor_readings_batch/1" do
+    test "inserts multiple processor readings", %{processor: processor, processor2: processor2} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{processor_id: processor.id, load_percent: 45.0, status: "ok", checked_at: now},
+        %{processor_id: processor2.id, load_percent: 92.0, status: "critical", checked_at: now}
+      ]
+
+      assert {2, nil} = Snmp.create_processor_readings_batch(entries)
+
+      readings = Repo.all(ProcessorReading)
+      assert length(readings) == 2
+
+      reading1 = Enum.find(readings, &(&1.processor_id == processor.id))
+      assert reading1.load_percent == 45.0
+      assert reading1.status == "ok"
+      assert reading1.checked_at == now
+      assert reading1.id
+      assert reading1.inserted_at
+
+      reading2 = Enum.find(readings, &(&1.processor_id == processor2.id))
+      assert reading2.load_percent == 92.0
+      assert reading2.status == "critical"
+    end
+
+    test "returns {0, nil} for empty list" do
+      assert {0, nil} = Snmp.create_processor_readings_batch([])
+      assert Repo.all(ProcessorReading) == []
+    end
+
+    test "generates unique UUIDs for each entry", %{processor: processor} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{processor_id: processor.id, load_percent: 10.0, status: "ok", checked_at: now},
+        %{processor_id: processor.id, load_percent: 20.0, status: "ok", checked_at: now}
+      ]
+
+      {2, nil} = Snmp.create_processor_readings_batch(entries)
+
+      readings = Repo.all(ProcessorReading)
+      ids = Enum.map(readings, & &1.id)
+      assert length(Enum.uniq(ids)) == 2
+    end
+
+    test "handles entries with nil load_percent", %{processor: processor} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{processor_id: processor.id, load_percent: nil, status: "error", checked_at: now}
+      ]
+
+      assert {1, nil} = Snmp.create_processor_readings_batch(entries)
+
+      [reading] = Repo.all(ProcessorReading)
+      assert reading.load_percent == nil
+      assert reading.status == "error"
+    end
+  end
+
+  describe "create_storage_readings_batch/1" do
+    test "inserts multiple storage readings", %{storage: storage, storage2: storage2} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{
+          storage_id: storage.id,
+          used_bytes: 5_000_000,
+          total_bytes: 10_000_000,
+          usage_percent: 50.0,
+          checked_at: now
+        },
+        %{
+          storage_id: storage2.id,
+          used_bytes: 2_000_000,
+          total_bytes: 8_000_000,
+          usage_percent: 25.0,
+          checked_at: now
+        }
+      ]
+
+      assert {2, nil} = Snmp.create_storage_readings_batch(entries)
+
+      readings = Repo.all(StorageReading)
+      assert length(readings) == 2
+
+      reading1 = Enum.find(readings, &(&1.storage_id == storage.id))
+      assert reading1.used_bytes == 5_000_000
+      assert reading1.total_bytes == 10_000_000
+      assert reading1.usage_percent == 50.0
+      assert reading1.checked_at == now
+      assert reading1.id
+      assert reading1.inserted_at
+
+      reading2 = Enum.find(readings, &(&1.storage_id == storage2.id))
+      assert reading2.used_bytes == 2_000_000
+      assert reading2.total_bytes == 8_000_000
+      assert reading2.usage_percent == 25.0
+    end
+
+    test "returns {0, nil} for empty list" do
+      assert {0, nil} = Snmp.create_storage_readings_batch([])
+      assert Repo.all(StorageReading) == []
+    end
+
+    test "generates unique UUIDs for each entry", %{storage: storage} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{
+          storage_id: storage.id,
+          used_bytes: 1000,
+          total_bytes: 2000,
+          usage_percent: 50.0,
+          checked_at: now
+        },
+        %{
+          storage_id: storage.id,
+          used_bytes: 1500,
+          total_bytes: 2000,
+          usage_percent: 75.0,
+          checked_at: now
+        }
+      ]
+
+      {2, nil} = Snmp.create_storage_readings_batch(entries)
+
+      readings = Repo.all(StorageReading)
+      ids = Enum.map(readings, & &1.id)
+      assert length(Enum.uniq(ids)) == 2
+    end
+
+    test "handles entries with nil optional fields", %{storage: storage} do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      entries = [
+        %{
+          storage_id: storage.id,
+          used_bytes: nil,
+          total_bytes: nil,
+          usage_percent: nil,
+          checked_at: now
+        }
+      ]
+
+      assert {1, nil} = Snmp.create_storage_readings_batch(entries)
+
+      [reading] = Repo.all(StorageReading)
+      assert reading.used_bytes == nil
+      assert reading.total_bytes == nil
+      assert reading.usage_percent == nil
+    end
+  end
+end