The "best plan" is dictated only by four things and only two of those really matter where performance is concerned...

1. Hardware - Nill effect. Double the speed on the hardware on a 12 hour slug query and you still have a 6 hour slug query.

2. Design - I certainly don't mean to downplay this but it's a simple fact that once a design has been cast, it takes an act of Congress to change it. So, usually, Nill effect because it can't be affected.

3. Indexes - Huge effect IF they can be used properly.

4. Code - This is where the true performance lies. Without doing this correctly, nothing else matters. Not hardware, not design, and usually not indexes. Write code the right way at all times. If it takes you too much time, then you need to get better at writing good code. 😛 The only way you can do that is to practice. A LOT! 😉