Optimize Feed Query N+1 Problem

[Techhackontime999]

Description

The feed page makes 30+ database queries per page due to N+1 query problems - each post triggers separate queries for likes, comments, and user data.

Steps to Reproduce

1. Enable Django Debug Toolbar or SQL logging
2. Navigate to the feed page
3. Count the number of SQL queries executed
4. Notice 30+ queries for 10 posts (should be <10)

Expected Behavior

The feed should use at most 3-5 queries regardless of the number of posts, using select_related and prefetch_related for all related data.

Root Cause

The feed view doesn't use select_related for user and prefetch_related for likes, comments, or �ttachments.

Files to Fix

• linkup/feed/views.py - Optimize the feed queryset with:
  • select_related('user', 'user__profile')
  • prefetch_related('likes', 'comments__user', 'attachments')
• linkup/feed/models.py - Add likes_count and comments_count properties using annotated queries

Acceptance Criteria

• Feed page uses <10 queries for 10 posts
• Like counts, comment counts, and user data load in bulk
• No visible change in functionality
• Performance improvement measurable with debug toolbar