title: Help me make this LINQ query faster please?
body: <p>To Set up the scenario, Lets say I have 100000 rows in the table and it grows more and more each day.  This queue currently takes over 2 seconds to retrieve only about 40 or 50 rows from the table.</p>
  
  <p>The data in this table are grouped by DateTime references so I start off grouping all the data by DateTime because this is the only equal value to other rows in the table.  Each group of rows could be anywhere from 1 row to 5 rows MAX.  I then select the grouped rows, pick apart the data and display it out to the user.  The problem I can see is that I cause an EXIST and a Group by in the SQL.  I must select all 40 rows at once to make the queue faster, but I pick each group out in a FOR loop. So how if any way can I make this queue faster?  Its the Laggiest of them all and my users are complaining about the 2 second wait time.  Please help.</p>
  
  <pre><code>(from yy in Data_Captured_Type_Militaries
      where yy.DateTime_Added &gt;= DateTime.UtcNow.AddHours(-72)
      (from xx in Data_Captured_Type_Militaries
      where xx.DateTime_Added &gt;= DateTime.UtcNow.AddHours(-72)
      group xx by xx.DateTime_Added into gg
      select gg.Key).Contains(yy.DateTime_Added)
      select new
      {
          yy.Elites,
          yy.DateTime_Added,
          yy.Uid,
          yy.Military_Location,
          yy.Province_ID,
          yy.Time_To_Return
      }).ToList()
  </code></pre>
  
  <p>What it translates to:</p>
  
  <pre><code>SELECT [t0].[Elites], [t0].[DateTime_Added], [t0].[uid] AS [Uid],[t0].[Military_Location], [t0].[Province_ID], [t0].[Time_To_Return]
  FROM [Data_Captured_Type_Military] AS [t0]
  WHERE (EXISTS (
      SELECT NULL AS [EMPTY]
      FROM (
          SELECT [t1].[DateTime_Added]
          FROM [Data_Captured_Type_Military] AS [t1]
          WHERE [t1].[DateTime_Added] &gt;= @p0
          GROUP BY [t1].[DateTime_Added]
          ) AS [t2]
      WHERE [t2].[DateTime_Added] = [t0].[DateTime_Added]
      )) AND ([t0].[DateTime_Added] &gt;= @p1)
  </code></pre>