title: Going .pluck crazy. What is a realistic limit on query with array
body: <p>I've used <code>.pluck(:id)</code> quite often (and <code>map</code> before it) to get a set of record ids. This is usually to get a set of related model records (e.g,, :people has_many :scores, as :assessed)</p>
  
  <p>Lets say I have 10,000 people, but a query on People limits it to say 1,000.</p>
  
  <pre><code>people_ids = people.pluck(:id) #people a relation/scoped
  scores = Score.where(:assessed_type =&gt; 'People', :assessed_id =&gt; people_ids)
  </code></pre>
  
  <p>There would be more to the Score query, but my basic question is querying with an array of say 1000 ids a bad idea?</p>
  
  <p>I should point out that the filtered Score query would be used to get a new set of People. This is a filter on People.</p>
  
  <p>I only have a few hundred records in my test DB, and that works fine - but there must be a point where psql or Rails is going to blow up. In production, I don't see going more that 1000 ids since People is automatically filter before this Score option is used.</p>