Examine performance under concurrency

Realistic scenarios frequently involve multiple analysts using the same db at the same time. Examine performance with 6+ queries going at once. Under Redshift's default options this will likely result in issues (http://docs.aws.amazon.com/redshift/latest/dg/cm-c-defining-query-queues.html) that shouldn't be experienced by BigQuery and experienced to a lesser extent on Snowflake.