Possible solutions to address the N+1 query issue

• Eager loading is a technique where you fetch the associated records in a single query, reducing the number of database trips.

# Eager loading solution using `includes`
@users = User.includes(:posts).all

@users.each do |user|
  puts "User: #{user.name}"
  puts "Posts:"
  user.posts.each do |post|
    puts post.title
  end
end

• Joins: You can use a SQL JOIN to retrieve both users and their posts in a single query.

# Join solution
@users = User.joins(:posts).select('users.*, posts.title as post_title')

@users.each do |user|
  puts "User: #{user.name}"
  puts "Post: #{user.post_title}"
end

• Use includes with nested associations: If you have multiple levels of associations, you can use nested includes to avoid multiple queries.

# Nested includes solution
@users = User.includes(posts: :comments).all

@users.each do |user|
  puts "User: #{user.name}"
  puts "Posts:"
  user.posts.each do |post|
    puts "Title: #{post.title}"
    puts "Comments:"
    post.comments.each do |comment|
      puts comment.text
    end
  end
end

By using these solutions, you can avoid N+1 queries and improve the performance of your application when dealing with associated data.

So, N+1 queries have been a consideration and concern in Ruby on Rails applications for many versions, and the best practices to avoid them have been part of the Rails development community’s guidelines. Always ensure you are using the most recent version of Ruby on Rails to take advantage of the latest performance improvements and optimizations. The Bullet or Prosopite gems can give a hand here by telling when to use eager loading and when not, and by adding a counter cache.