MySQL 8.0.30 on
Rocky Linux 9
For slow MySQL queries in general, not for a speciffic one, is there a way to tell if query speed was bottlenecked by storage speed, cpu speed, or maybe even ram memory speed ? (mainly storage vs cpu).
Maybe there are certain mysql status variables related to tracking this ?
For example I ran a slow query (~30 seconds) while looking at disk
iotop read speed, and because I seen it never read faster than around 20% of maximum ssd read speed, I assume that faster disk would not help speeding up my queries too much, and that maybe CPU (processing the data, not reading it) was the bottleneck.
What are some better ways to do similar tests ?
I also tried similar queries on 2 different SSDs, one having double read speed than the other, but I seen no performance differences, I always thought the storage is "weakest link" but now I need to do more tests.