Question 1: Pick the Problematic Plan: someone hands you a pair of queries, and you get the estimated query plans. (Perhaps you get the estimated plans from SSMS, or from sp_BlitzCache, or from your monitoring tool.) Which one of these two should you focus on tuning first, Query 1 or Query 2?
Question 2: on an estimated plan, what does the thickness of the colored arrow represent?
Question 3: on an actual plan, what does the thickness of the colored arrow represent?
Tune in next week for the answers!