title: In BigQuery flat-rate pricing, how are the purchased slots shared among different concurrent users?
body: <p>Suppose that 500 slots have been purchased, user1 launches a BigQuery query that uses all 500 slots. In the middle of the query processing, user2 launches another query that, say, will require 200 slots. The question is basically a scheduling and sharing one: how the slots are to be shared between the users. For instance, will the query from user2 wait for slots to be freed
  after the query from user1 finishes, or at least after it requires less slots during processing? Or will the query from user2 grab some slots for its execution even before the query from user1 finishes, and before it requires less slots during its processing, thus effectively suspending/interrupting some execution &quot;threads&quot; for user1 and reallocating the saved slots to user2?</p>
  <p>A related question is, regardless of which sharing algorithm in use, whether there is a way to limit a user's ask for the number of slots in his query executions?</p>
  <p>Thanks.</p>