ASH is one of the most powerful instrumentation related feature Oracle ever introduced and yet it is one the least explored feature. In this article, I explain how ASH can be used for troubleshooting, performance tuning, root cause analysis, scalability and capacity analysis.

I also explain key performance related data that is only captured in ASH but not available in any other v$ views, drawbacks of do it yourself ASH approach, and how ASH can be drilled down even further when coupled with real application testing.