Question

I’m trying to display a forum/category. I need to get the latest posts. The problem is that I also need data on the user for each post as well as the latest reply.

db.post.find({
  "inForum": forumID,
},
{
  'sort': [['date', -1]]
},
function(err, cursor) {
  cursor.count(function(err, count) {
    cursor.skip(skip).limit(20).toArray(function(err, posts) {
      var complete = _.after(nodes.length, function () {
        res.send(posts)
      });

      // for every post get its author info and the latest post info
      posts.forEach(function (post) {
        var users = _.pluck(posts, 'user');
        user.load(users, function (profiles) {
          _.each(posts,
          function(post, k) {
            if (profiles[post.user]) post.fieldAvatar = profiles[post.user].fieldAvatar;
          });

          if (post.latestReply) {
            post.load(post.latestReply.id, function (latestReply) {
              if (latestReply) post.latestReply = latestReply
              complete()
            })
          }
          else {
            complete()
          }
        })
      })
    });
  })
})

This is what I’m doing and it seems really slow / really inelegant to me. Am I doing this correctly and is there any advice for speeding this up?

Thanks.

Answer 1

The best thing you should do here is to embed some information for the author of the posts (username & email or avatar) into those posts so that you don’t make multiple queries to the database, one should suffice (sure you have some duplicate data, but the performance is optimal).

If you don’t want to / can’t do that you can also modify your second query to find all authors in [array_of_ids_of_the_posts]. That would reduce your [number_of_posts] queries into only one.