As a reminder, the immediate, wait option is normal Oracle behavior and should serve as a baseline. As expected and as Table 8-1 shows, the top wait event is clearly log file sync, which is the server process waiting for the commit to finish. The log file sync percentage change is not overly relevant because the workload was allowed to increase. So, any response-time gain could be offset by an increase in throughput. This trade-off will be discussed in detail in the next chapter. The second top wait event, also shown in Table 8-1, was always log file parallel write, which is the time the log writer background process is actually waiting for the write to complete.

As we expect buffered asynchronous writes, the batch, nowait option clearly provided the most workload processed per second. In fact, compared to the immediate, wait baseline, the batch, nowait option commit rate was more than 34 times greater. That is an amazing performance improvement!

While the batch, nowait option appears to have a higher commit rate than the immediate, nowait option, I ran a statistical significance test6 to ensure any workload difference could not be attributed to randomness. The statistical significance test clearly indicated (99.7% confidence level) that the batch, nowait option did indeed process more commits per second than the immediate, nowait option.