Smart Scans efficiency chart for Oracle Engineered Systems
If you manage an Oracle Engineered System you may wonder how well your Smart Scans are performing. Are you taking full advantage of Exadata Optimizations? If so, how do you measure them?
Sample chart below is from a data warehouse DW application. It shows in blue that bytes eligible for offloading are around 95%, which denote a large amount of desired full scans. We see in red that between 80 and 95% of the expected I/O did not hit the network, i.e. it was saved (incorrectly referred as IO Saved since what is saved is the network traffic). And in yellow we see between 30 and 45% of the IO was entirely avoided due to Storage Indexes. So, with 80-95% of the expected data not going through the network and 30-45% of IO entirely eliminated, I could conclude that Exadata Optimizations are well applied on this DW.
If you have SQL*Plus access to an Engineered System, and want to produce a chart like this, simply download and execute free tool eDB360. This tool installs nothing on your database!