I have two models with has_many and belongs_to defined.  The following two queries always produce exactly n+1 queries

A.where(:ids.in => ids).includes(:bs).collect{|x| x.bs.count}

A.where(:ids.in => ids).collect{|x| x.bs.count}

The includes has no effect.  Here are the specific relations:

class Case

  has_many :case_statuses, dependent: :destroy

 ...

class CaseStatus

  belongs_to :case, index: true, inverse_of: :case_statuses

And given an array of ids, ids (in this case there are 10 ids), both queries produce exaclty 11 mongo queries:

Case.where(:id.in => ids).includes(:case_statuses).collect{|x| x.case_statuses.count}

Case.where(:id.in => ids).collect{|x| x.case_statuses.count}

i.e. includes does not reduce the fired mongo queries from 11 to 1 as expected. 

Thanks for any help,
kevin