Timeline for CPU,Memory and disk I/O utilization for each query in mysql
Current License: CC BY-SA 3.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 24, 2019 at 0:13 | comment | added | Rick James | @ToolmakerSteve - If you have a slowlog covering 1000 instances of a particular query, nearly all will have about the same elapsed time. But a few may take 10 times as long. If, for example, long_qiuery_time = 1 (second) and that query normally takes 0.2 sec, a few instances of those 1000 will show up in the log. | |
| Oct 24, 2019 at 0:09 | comment | added | Rick James | @ToolmakerSteve - Yes, any other activity can impact the elapsed time. If your CPU has 8 cores, you need 9 things running for that to have much effect. If other queries are touching the same rows, etc, then locks can block one or the other. | |
| Oct 23, 2019 at 12:47 | comment | added | ToolmakerSteve | Re "'elapsed' is more interesting than CPU vs I/O". Question: When there are multiple active connections on a server, will "elapsed" time depend on server load? Do I need to test during a quiet period, to get an accurate sense of the cpu time actually consumed by each query? I'll test it both during busy and quiet times, so I'll know then, but I thought it would be good for others to know "a priori" what "elapsed time" really measures. | |
| Mar 11, 2018 at 10:39 | history | answered | Rick James | CC BY-SA 3.0 |