Taken from Slide 26 of the Search Optimization in 500 Easy Steps presentation given at .conf2014 by Julian Harty.
How can I determine if my search is Dense or Sparse?
Use Job Inspector…
scanCount = The number of events that are scanned or read off disk.
eventCount = Number of events that are returned to base search
• For dense searches scanCount ~= eventCount.
• For sparse searches, scanCount >> eventCount.