Monitoring Savings from Smart Scan

Oracle provides some new measures in the standard V$ performance views that allow you to see how much I/O is being saved by the use of Smart Scan technology. The statistics are shown in Table 3-1.

The EXPLAIN PLAN, shown in Figure 3-2, gives an indication of the steps in an execution plan that will benefit from Smart Scan.

You can see that steps 12 and 14 have the word STORAGE in the name of their operation. There are two important things to understand about the use of these operation names. The first relevant fact is that you can control whether the EXPLAIN PLAN displays these types of operation names. The setting of the CELL_OFFLOAD_PLAN_DISPLAY parameter, set with an ALTER SYSTEM or ALTER SESSION command, controls the display with the following settings: