Performance Schema file_summary_by_event_name Table
The Performance Schema file_summary_by_event_name table contains file events summarized by event name. It contains the following columns:
| Column | Description |
|---|---|
EVENT_NAME | Event name. |
COUNT_STAR | Number of summarized events |
SUM_TIMER_WAIT | Total wait time of the summarized events that are timed. |
MIN_TIMER_WAIT | Minimum wait time of the summarized events that are timed. |
AVG_TIMER_WAIT | Average wait time of the summarized events that are timed. |
MAX_TIMER_WAIT | Maximum wait time of the summarized events that are timed. |
COUNT_READ | Number of all read operations, including FGETS, FGETC, FREAD, and READ. |
SUM_TIMER_READ | Total wait time of all read operations that are timed. |
MIN_TIMER_READ | Minimum wait time of all read operations that are timed. |
AVG_TIMER_READ | Average wait time of all read operations that are timed. |
MAX_TIMER_READ | Maximum wait time of all read operations that are timed. |
SUM_NUMBER_OF_BYTES_READ | Bytes read by read operations. |
COUNT_WRITE | Number of all write operations, including FPUTS, FPUTC, FPRINTF, VFPRINTF, FWRITE, and PWRITE. |
SUM_TIMER_WRITE | Total wait time of all write operations that are timed. |
MIN_TIMER_WRITE | Minimum wait time of all write operations that are timed. |
AVG_TIMER_WRITE | Average wait time of all write operations that are timed. |
MAX_TIMER_WRITE | Maximum wait time of all write operations that are timed. |
SUM_NUMBER_OF_BYTES_WRITE | Bytes written by write operations. |
COUNT_MISC | Number of all miscellaneous operations not counted above, including CREATE, DELETE, OPEN, CLOSE, STREAM_OPEN, STREAM_CLOSE, SEEK, TELL, FLUSH, STAT, FSTAT, CHSIZE, RENAME, and SYNC. |
SUM_TIMER_MISC | Total wait time of all miscellaneous operations that are timed. |
MIN_TIMER_MISC | Minimum wait time of all miscellaneous operations that are timed. |
AVG_TIMER_MISC | Average wait time of all miscellaneous operations that are timed. |
MAX_TIMER_MISC | Maximum wait time of all miscellaneous operations that are timed. |
I/O operations can be avoided by caching, in which case they will not be recorded in this table.
You can TRUNCATE the table, which will reset all counters to zero.
Example
SELECT * FROM file_summary_by_event_name\G
...
*************************** 49. row ***************************
EVENT_NAME: wait/io/file/aria/MAD
COUNT_STAR: 60
SUM_TIMER_WAIT: 397234368
MIN_TIMER_WAIT: 0
AVG_TIMER_WAIT: 6620224
MAX_TIMER_WAIT: 16808672
COUNT_READ: 0
SUM_TIMER_READ: 0
MIN_TIMER_READ: 0
AVG_TIMER_READ: 0
MAX_TIMER_READ: 0
SUM_NUMBER_OF_BYTES_READ: 0
COUNT_WRITE: 0
SUM_TIMER_WRITE: 0
MIN_TIMER_WRITE: 0
AVG_TIMER_WRITE: 0
MAX_TIMER_WRITE: 0
SUM_NUMBER_OF_BYTES_WRITE: 0
COUNT_MISC: 60
SUM_TIMER_MISC: 397234368
MIN_TIMER_MISC: 0
AVG_TIMER_MISC: 6620224
MAX_TIMER_MISC: 16808672
*************************** 50. row ***************************
EVENT_NAME: wait/io/file/aria/control
COUNT_STAR: 3
SUM_TIMER_WAIT: 24055778544
MIN_TIMER_WAIT: 0
AVG_TIMER_WAIT: 8018592848
MAX_TIMER_WAIT: 24027262400
COUNT_READ: 1
SUM_TIMER_READ: 24027262400
MIN_TIMER_READ: 0
AVG_TIMER_READ: 24027262400
MAX_TIMER_READ: 24027262400
SUM_NUMBER_OF_BYTES_READ: 52
COUNT_WRITE: 0
SUM_TIMER_WRITE: 0
MIN_TIMER_WRITE: 0
AVG_TIMER_WRITE: 0
MAX_TIMER_WRITE: 0
SUM_NUMBER_OF_BYTES_WRITE: 0
COUNT_MISC: 2
SUM_TIMER_MISC: 28516144
MIN_TIMER_MISC: 0
AVG_TIMER_MISC: 14258072
MAX_TIMER_MISC: 27262208
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