ActiveRecord find_each combined with limit and order

Question

I\'m trying to run a query of about 50,000 records using ActiveRecord\'s find_each method, but it seems to be ignoring my other parameters like so:

Answer 1

You can iterate backwards by standard ruby iterators:

Thing.last.id.step(0,-1000) do |i|
  Thing.where(id: (i-1000+1)..i).order('id DESC').each do |thing|
    #...
  end
end

Note: +1 is because BETWEEN which will be in query includes both bounds but we need include only one.

Sure, with this approach there could be fetched less than 1000 records in batch because some of them are deleted already but this is ok in my case.