Deletes incur high write lock. This will likely change in 2.6 in some ways. But dropping a collection/database will still be extremely fast. This ticket is to create a docs page to cover this.

• Drop collections/database
• TTL (if time period is known) to spread out deletes (docs all expiring at the same time isn't good)
• Throttle deletes
  • pause between batches
  • w:majority to throttle