Bulk Insert records into Active Record table

Question

I found that my Model.create! statements were taking a very long time to run when I added a large number of records at once. Looked at ActiveRecord-Import but

Answer 1

Using a transaction speeds up bulk inserts a lot!

Model.transaction do
    many.times{ Model.create! }
end

If multiple Models are involved, do a Model.transaction for each model, which is affected:

Model1.transaction do
    Model2.transaction do
        many.times do
            m1 = Model1.create!
            m1.add_model2
        end
    end
end