fix: optimize visualization hot paths and refine bgp brief workspace

backend/app/api/v1/dashboard.py

@@ -118,58 +118,77 @@ async def get_stats(
     built_in_count = len(COLLECTOR_INFO)
     built_in_active = built_in_count  # Built-in are always "active" for counting purposes
 
-    # Count custom configs from database
-    result = await db.execute(select(func.count(DataSourceConfig.id)))
-    custom_count = result.scalar() or 0
-
     result = await db.execute(
-        select(func.count(DataSourceConfig.id)).where(DataSourceConfig.is_active == True)
+        select(
+            func.count(DataSourceConfig.id).label("custom_count"),
+            func.sum(
+                case((DataSourceConfig.is_active == True, 1), else_=0)
+            ).label("custom_active"),
+        )
     )
-    custom_active = result.scalar() or 0
+    datasource_stats = result.one()
+    custom_count = datasource_stats.custom_count or 0
+    custom_active = datasource_stats.custom_active or 0
 
     # Total datasources
     total_datasources = built_in_count + custom_count
     active_datasources = built_in_active + custom_active
 
-    # Tasks today (from database)
     result = await db.execute(
-        select(func.count(CollectionTask.id)).where(CollectionTask.started_at >= today_start)
-    )
-    tasks_today = result.scalar() or 0
-
-    result = await db.execute(
-        select(func.count(CollectionTask.id)).where(
-            CollectionTask.status == "success",
-            CollectionTask.started_at >= today_start,
+        select(
+            func.count(CollectionTask.id).label("tasks_today"),
+            func.sum(
+                case(
+                    (CollectionTask.status == "success", 1),
+                    else_=0,
+                )
+            ).label("success_tasks"),
         )
+        .where(CollectionTask.started_at >= today_start)
     )
-    success_tasks = result.scalar() or 0
+    task_stats = result.one()
+    tasks_today = task_stats.tasks_today or 0
+    success_tasks = task_stats.success_tasks or 0
     success_rate = (success_tasks / tasks_today * 100) if tasks_today > 0 else 0
 
-    # Alerts
     result = await db.execute(
-        select(func.count(Alert.id)).where(
-            Alert.severity == AlertSeverity.CRITICAL,
-            Alert.status == "active",
+        select(
+            func.sum(
+                case(
+                    (
+                        (Alert.severity == AlertSeverity.CRITICAL)
+                        & (Alert.status == "active"),
+                        1,
+                    ),
+                    else_=0,
+                )
+            ).label("critical_alerts"),
+            func.sum(
+                case(
+                    (
+                        (Alert.severity == AlertSeverity.WARNING)
+                        & (Alert.status == "active"),
+                        1,
+                    ),
+                    else_=0,
+                )
+            ).label("warning_alerts"),
+            func.sum(
+                case(
+                    (
+                        (Alert.severity == AlertSeverity.INFO)
+                        & (Alert.status == "active"),
+                        1,
+                    ),
+                    else_=0,
+                )
+            ).label("info_alerts"),
         )
     )
-    critical_alerts = result.scalar() or 0
-
-    result = await db.execute(
-        select(func.count(Alert.id)).where(
-            Alert.severity == AlertSeverity.WARNING,
-            Alert.status == "active",
-        )
-    )
-    warning_alerts = result.scalar() or 0
-
-    result = await db.execute(
-        select(func.count(Alert.id)).where(
-            Alert.severity == AlertSeverity.INFO,
-            Alert.status == "active",
-        )
-    )
-    info_alerts = result.scalar() or 0
+    alert_stats = result.one()
+    critical_alerts = alert_stats.critical_alerts or 0
+    warning_alerts = alert_stats.warning_alerts or 0
+    info_alerts = alert_stats.info_alerts or 0
 
     response = {
         "total_datasources": total_datasources,