MySQL 8.0.29
Source Code Documentation
pfs_histogram.cc File Reference

Miscellaneous global dependencies (implementation). More...

Macros

#define BUCKET_BASE_TIMER   (10 * 1000 * 1000)
 Histogram base bucket timer, in picoseconds. More...
 
#define BUCKET_BASE_FACTOR   1.0471285480508996
 Bucket factor. More...
 

Variables

PFS_histogram_timers g_histogram_pico_timers
 Timer values used in histograms. More...
 

Detailed Description

Miscellaneous global dependencies (implementation).

Macro Definition Documentation

◆ BUCKET_BASE_FACTOR

#define BUCKET_BASE_FACTOR   1.0471285480508996

Bucket factor.

histogram_timer[i+1] = BUCKET_BASE_FACTOR * histogram_timer[i] The value is chosen so that BUCKET_BASE_FACTOR ^ 50 = 10, which corresponds to a 4.7 percent increase for each bucket, or a power of 10 increase for 50 buckets.

◆ BUCKET_BASE_TIMER

#define BUCKET_BASE_TIMER   (10 * 1000 * 1000)

Histogram base bucket timer, in picoseconds.

Currently defined as 10 micro second.

Variable Documentation

◆ g_histogram_pico_timers

PFS_histogram_timers g_histogram_pico_timers

Timer values used in histograms.

Timer values are expressed in picoseconds.

timer[0] = 0 timer[1] = BUCKET_BASE_TIMER

From then, timer[N+1] = BUCKET_BASE_FACTOR * timer[N]

The last timer is set to infinity.