What's the 'Rails 4 Way' of finding so

Question

User.find(:all, :order => "RANDOM()", :limit => 10) was the way I did it in Rails 3.

User.all(:order => "RANDOM()", :limit => 10) is how I thought Rails 4 would do it, but this is still giving me a Deprecation warning:

DEPRECATION WARNING: Relation#all is deprecated. If you want to eager-load a relation, you can call #load (e.g. `Post.where(published: true).load`). If you want to get an array of records from a relation, you can call #to_a (e.g. `Post.where(published: true).to_a`).

Answer 1

You could call .sample on the records, like: User.all.sample(10)

Answer 2

For MYSQL this worked for me:

User.order("RAND()").limit(10)

Answer 3

Strongly Recommend this gem for random records, which is specially designed for table with lots of data rows:

https://github.com/haopingfan/quick_random_records

All other answers perform badly with large database, except this gem:

1. quick_random_records only cost 4.6ms totally.

2. the accepted answer User.order('RAND()').limit(10) cost 733.0ms.

3. the offset approach cost 245.4ms totally.

4. the User.all.sample(10) approach cost 573.4ms.

Note: My table only has 120,000 users. The more records you have, the more enormous the difference of performance will be.

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UPDATE:

Perform on table with 550,000 rows

1. Model.where(id: Model.pluck(:id).sample(10)) cost 1384.0ms

2. gem: quick_random_records only cost 6.4ms totally