title: Combine two integer vectors
body: <p>I have two integer vectors. First one contains all of my userIds (lets say the count=100) and second vector contains users that did something. I need a result array with the size of 100  and if that user is in the second list the value will be true, if not the value will be false. </p>
  
  <p>Let me draw this:</p>
  
  <pre><code>userVector  filteredUserVector  theResultArray
  1001        1001                true
  1002        1002                true
  1003        1004                false
  1004        1006                true
  1005                            false
  1006                            true
  1007                            false
  </code></pre>
  
  <p>And I'm doing this with a code like this:</p>
  
  <pre><code> var theResultArray = (FROM user IN userVector  
                                JOIN login IN filteredUserVector ON user equals login INTO prodGroup
                                FROM item IN prodGroup.DefaultIfEmpty()
                                SELECT item != 0).ToArray();
  </code></pre>
  
  <p>This works. But my problem is:</p>
  
  <p>The first vectors have 185569 integer value and im doing this in a for loop. In every loop my <code>filteredUserVector</code> changes. My loop count is 40.000 and in 30k s it crashes with memory exception.</p>
  
  <p>the code whole code block:</p>
  
  <pre><code>loop starts:
      var filteredUserVector=anotherDataSource.select(some where conditions)
       var theResultArray = (FROM user IN userVector  
                                JOIN login IN filteredUserVector ON user equals login INTO prodGroup
                                FROM item IN prodGroup.DefaultIfEmpty()
                                SELECT item != 0).ToArray();
  
      ..some code..
  
      bigStore.Add(theResultArray)
  loop ends
  </code></pre>
  
  <p>I hope I could explain my problem. 
  How can I combine in a way that I want efficiently?</p>