Why does Foglight reporting a high latency?
What Oracle object does Foglight query to run the above test?
How often does this test fire?
If there are very high lost block counts (relative to blocks received) – or if the time associated with lost blocks becomes significant compared to total database time – then the most likely cause is a network hardware issue. This can be as simple as a poorly mounted network card, crimped networking cables or faulty network components.
The SQL query itself it proprietary, but what we do is total various sys.v_$sysstat