title: SQL query performance: Running multiple instances of same query
body: <p>First scenario: I run a query in one instance in SQL server.
  Second scenario: I run the same query in two instances, i.e., running the same script but in two instances.</p>
  
  <p>Assume that both queries start with the cache clean.  Will the second scenario take longer to complete?</p>
  
  <p>Basically my question is whether using the database in two instances results in slower performance than using the database in only one instance.</p>
  
  <p>Thanks!</p>