bloat_fail.rb

gistfile1.builder

## FAIL
## Attempting to iterate (chunkily) over 2000 records and instantiating 1 single object per iteration 
## All of the below bloat to > 200MB on rails 2.3.x

# iterates in chunks of 10 
User.find_each(:batch_size => 10) do |user|
  date = user.posts.find(:first).created_at
end

# iterates in chunks of 100 
User.find_each(:batch_size => 10) do |user|
  date = user.posts.find(:first).created_at
end

# iterates with will_paginate 
User.paginated_each do |user|
  date = user.posts.find(:first).created_at
end

# Not going through the relationship doesn't make a difference
User.find_each(:batch_size => 10) do |user|
  date = Posts.find(:first, :conditions =>{:user => user}).created_at
end

# Nor does storing the result in a var with a larger scope
date = []
User.find_each(:batch_size => 10) do |user|
  date << user.posts.find(:first).created_at
end

# Or heck, not storing the result at all
User.find_each(:batch_size => 10) do |user|
  user.posts.find(:first).created_at
end