How to speed up performance by avoiding to query Mongoid multiple times?

Question

I have approx. 10 million Article objects in a Mongoid database. The huge number of Article objects makes the queries quite time consuming to perform.

As exemplified below, I am registering for each week (e.g. 700 days from now .. 7 days from now, 0 days from now) how many articles are in the database.

But for every query I make, the time consumption is increased, and Mongoid's CPU usage quickly reaches +100%.

articles = Article.where(published: true).asc(:datetime)
days = Date.today.mjd - articles.first.datetime.to_date.mjd

days.step(0, -7) do |n|
  current_date            = Date.today - n.days
  previous_articles       = articles.lt(datetime: current_date)
  previous_good_articles  = previous_articles.where(good: true).size
  previous_bad_articles   = previous_articles.where(good: false).size
end

Is there a way to save the Article objects to memory, so only need to call the database on the first line?

Answer 1

A MongoDB database is not build for that.

I think the best way is to run daily a script that creates your data for that day and save it in a Redis Database http://www.redis.io

Redis stores your data in the server memory, so you can access it every time of the day. And is very quick.