I get asked regularly what does Embarcadero's SQL tuner have that is any different than Quest's SQL tuner. The HUGE difference between Quest and Embarcadero’s approach is the Visual SQL Tuning (VST). Without VST most automated SQL tuning turns into dead ends. Why dead ends? Because in general the databases are going to correctly optimize queries. Queries are rarely incorrectly optimized. In those rare instances where a database get’s it wrong, then the approach of blindly generating and testing alternative execution plans can be helpful but only helpful in the case where queries are small enough that many alternative cases can be tested.If on the other hand the query is long running say, a day, then testing alternative cases will not lead to results for easily several days. On the other hand with VST diagram we can quickly identified the best execution path using the diagram and guide the database to use this path.
Also for queries that can’t be optimized by the database because the are inherently slow, intractable or badly written - then what do you do? Generating alternative execution cases is pointless. What is going to help you quickly and easily understand the query and what the problems are? The solution is VST diagrams which only Embarcadero has in DB Optimizer.
Not only does DB Optimizer generate and test alternative execution plans, analyze indexes, suggest missing indexes, verify table statistics, analyze columns for histogram candidates and the have the powerful VST diagrams, DB Optimizer also has database load profiling, detail drilldown, load testing and sql editing with error flagging, automated error fixing, type ahead and code templates. All of this is wrapped in the Eclipse IDE and is a single executable supporting the same interface across Oracle, SQL Server, Sybase and DB2.