# Migration: counter cache & "reset\_column\_information"

**URL:** <https://www.ruby-forum.com/t/migration-counter-cache-reset-column-information/50307>\
**Category:** Rails\
**Created:** [December 15, 2005, 1:09am UTC](https://www.ruby-forum.com/t/migration-counter-cache-reset-column-information/50307 "2005-12-15T01:09:47Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![aravet](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/49beb7/32.png) [@aravet](https://www.ruby-forum.com/u/aravet)\
**Post date:** [December 15, 2005, 1:09am UTC](https://www.ruby-forum.com/t/migration-counter-cache-reset-column-information/50307/1 "2005-12-15T01:09:47Z")

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To speed up

\<%= @project.members\_count %\>

, I added a counter cache to the ‘projects’ table with the migration  
below:

def self.up  
add\_column “projects”, “members\_count”, :string, :default =\> “0”  
Project.reset\_column\_information  
Project.find(:all).each do |p|  
p.update\_attribute :members\_count , p.members.count  
end  
end

Question:  
Is “Project.reset\_column\_information” required in the migration?

Alain

(Note: For info, I modified the ‘Member’ model accordingly:  
class Member \< ActiveRecord::Base  
belongs\_to :project, :counter\_cache =\> true  
)

---

<div class="post-metadata">

**Author:** ![aravet](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/49beb7/32.png) [@aravet](https://www.ruby-forum.com/u/aravet)\
**Post date:** [December 16, 2005, 12:10am UTC](https://www.ruby-forum.com/t/migration-counter-cache-reset-column-information/50307/2 "2005-12-16T00:10:31Z")

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Anybody?