User enters a fairly simple SQL statement in to the SQL Optimizer Tuning Lab. Executing the query or it's alternatives show 00.000 seconds total elapsed time and no colored bars, where slower queries than original are suppose to be navy blue, faster queries are green, and the original query is teal.
This is because some SQL statements run faster than SQL Optimizer can measure, thus SQL Optimizer displays that they run 00.000 seconds instead of a smaller fraction of a second. This is request CR0228950.
An enhancement request has been submitted to the development team to implement a message letting users know that the query ran faster than can be measured.