activerecord-import is a library for bulk inserting data using ActiveRecord. By default with ActiveRecord, in order to insert multiple records you have to perform individual save operations on each model, like so:
10.times do |i|
Book.create! :name => "book #{i}"
end
This may work fine if all you have is 10 records, but if you have hundreds, thousands, or millions of records it can turn into a nightmare. This is where activerecord-import comes into play. Here's the equivalent behaviour using the #import method:
Maybe, just maybe you're thinking, why do I have do instantiate ActiveRecord objects? Will that perform validations? What if I don't want validations? What if I want to take advantage of features like MySQL's on duplicate key update? Well, activerecord-import handles all of these cases and more!
For more documentation on the matter you can refer to two places:
This library replaces the ar-extensions library and is compatible with Rails 3. It provides the exact same API for importing data, but it does not include any additional ar-extensions functionality.