The R/s dataflow depicts the rate at which database agents are reading pages from the database or partition into buffer pools. These reads are synchronous because they performed as part of the processing of program instructions.
At each refresh, Spotlight captures the number of synchronous reads per second at the database or partition level.
The line graph that overlays the dataflow plots the synchronous read rate captured over the series of refreshes that have occurred during the Spotlight session.
Click the R/s dataflow to open the Databases drilldown. This drilldown provides details about the database or partition that you are currently monitoring. The I/O Activity tab on the drilldown is in immediate focus to help you pinpoint I/O flow problems in the database or partition.