V$SERVICE_STATS displays a minimal set of performance statistics. These call rate statistics are used for making run-time routing decisions, for tracking service levels, and for per-instance diagnostics per call rate. The elapsed timing for each call provides a relative value across instances for how well a node is processing SQL calls issued under a service name.
When aggregation is enabled for the Service Name, then this view provides the timing and work done for calls issued for the whole service.
Service name hash from V$SERVICES
Service name from V$SERVICES
Derived statistic name from V$STATNAME and V$SESS_TIME_MODEL