Minimizing calls to database in rails

Posted by ming yeow on Stack Overflow See other posts from Stack Overflow or by ming yeow
Published on 2010-05-22T17:04:07Z Indexed on 2010/05/22 17:10 UTC
Read the original article Hit count: 145

Filed under:

ruby-on-rails

|

ruby

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Performance

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memcached

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database-queries

Hi guys, i am familiar with memcached and eager loading, but neither seems to solve the problem i am facing.

My main performance lag comes from hundreds of data retrieval calls from the database. The tricky thing is that I do not know which set of users i need to retrieve until i have several steps of computation.

I can refactor my code, but i was wondering how you experts handle this situation? I think it should be a fairly common situation

def newsfeed

  - find out which users i need
  - retrieve those users via DB

  - find out which events happened for these users
  - for each of those events
        - retrieve new set of users

  - find out which groups are relevant
  - for each of those groups
        - retrieve new set of users 

  - etc, etc 

end

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