3 ms·
Am I misunderstanding something? If one CPU cycle accounts for 27 seconds, then the savings of 10 seconds suggest we saved one half of a CPU cycle per iteration
by martin_ 11y ago
Am I misunderstanding something? If one CPU cycle accounts for 27 seconds, then the savings of 10 seconds suggest we saved one half of a CPU cycle per iteration? Or do the queries not touch every row?
Optimizing data types and minimizing locks seem like general optimization tips, I was hoping for more advanced techniques for 100B rows.
- joefkelley 11y agoOne CPU cycle per row saves 27 seconds of one CPU's time. That 10 seconds was saved on every CPU in the cluster. So if there were 50 CPUs, that's 500 seconds, or ~20 cycles per record, by the original calculation. In reality, the change in data type probably optimized disk access more than it did number of CPU cycles. That can often be more of a bottleneck.