What is query performance?

Answer: There are two measures of query performance:

• Response time: The time to get an answer to an individual query

• Throughput: The number of queries that can be run in any given time period; for example, queries each second

These two measures are related, but they are not the same. In a heavily loaded system, you want maximum throughput, whereas in a relatively lightly loaded system, you probably want minimum response time. Also, some applications require a query to deliver all hits to the user, whereas others only require the first 20 hits from an ordered set. It is important to distinguish between these two scenarios.