fix: optimize caldav events query

app/models/calendar-events.js

@@ -201,6 +201,9 @@ const CalendarEvents = new mongoose.Schema(
 
 // TODO: test that timezone in VCALENDAR works properly
 
+// Composite index for efficient querying of non-deleted events per calendar
+CalendarEvents.index({ calendar: 1, deleted_at: 1 });
+
 CalendarEvents.plugin(sqliteVirtualDB);
 CalendarEvents.plugin(validationErrorTransform);
 

caldav-server.js

@@ -1715,13 +1715,14 @@ class CalDAV extends API {
 
   async getEventsForCalendar(
     ctx,
-    { calendarId, principalId, user, fullData, showDeleted }
+    { calendarId, principalId, user, fullData, showDeleted, limit }
   ) {
     ctx.logger.debug('getEventsForCalendar', {
       calendarId,
       principalId,
       user,
-      fullData
+      fullData,
+      limit
     });
 
     const calendar = await this.getCalendar(ctx, {
@@ -1735,14 +1736,24 @@ class CalDAV extends API {
         ctx.translateError('CALENDAR_DOES_NOT_EXIST')
       );
 
-    let events = await CalendarEvents.find(this, ctx.state.session, {
+    // Build query to filter deleted events at database level
+    const query = {
       calendar: calendar._id
-    });
+    };
+
+    // Filter out deleted events at DB level for performance
+    if (!showDeleted) {
+      query.deleted_at = null;
+    }
+
+    // Apply limit if specified (default to 10000 to prevent massive queries)
+    const maxLimit = limit || 10000;
 
-    // TODO: improve this with search directly on sql
-    if (!showDeleted) events = events.filter((e) => !_.isDate(e.deleted_at));
+    const events = await CalendarEvents.find(this, ctx.state.session, query)
+      .limit(maxLimit)
+      .sort({ eventId: 1 });
 
-    ctx.logger.debug('events', { events });
+    ctx.logger.debug('events', { count: events.length, limit: maxLimit });
 
     return events;
   }