Performance Schema file_summary_by_instance Table
The Performance Schema file_summary_by_instance table contains file events summarized by instance. It contains the following columns:
| Column | Description |
|---|---|
FILE_NAME | File name. |
EVENT_NAME | Event name. |
OBJECT_INSTANCE_BEGIN | Address in memory. Together with FILE_NAME and EVENT_NAME uniquely identifies a row. |
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_instance\G
...
*************************** 204. row ***************************
FILE_NAME: /var/lib/mysql/test/db.opt
EVENT_NAME: wait/io/file/sql/dbopt
OBJECT_INSTANCE_BEGIN: 140578961971264
COUNT_STAR: 6
SUM_TIMER_WAIT: 39902495024
MIN_TIMER_WAIT: 177888
AVG_TIMER_WAIT: 6650415692
MAX_TIMER_WAIT: 21026400404
COUNT_READ: 1
SUM_TIMER_READ: 21026400404
MIN_TIMER_READ: 21026400404
AVG_TIMER_READ: 21026400404
MAX_TIMER_READ: 21026400404
SUM_NUMBER_OF_BYTES_READ: 65
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: 5
SUM_TIMER_MISC: 18876094620
MIN_TIMER_MISC: 177888
AVG_TIMER_MISC: 3775218924
MAX_TIMER_MISC: 18864558060
*************************** 205. row ***************************
FILE_NAME: /var/log/mysql/mariadb-bin.000157
EVENT_NAME: wait/io/file/sql/binlog
OBJECT_INSTANCE_BEGIN: 140578961971968
COUNT_STAR: 6
SUM_TIMER_WAIT: 73985877680
MIN_TIMER_WAIT: 251136
AVG_TIMER_WAIT: 12330979468
MAX_TIMER_WAIT: 73846656340
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: 2
SUM_TIMER_WRITE: 62583004
MIN_TIMER_WRITE: 27630192
AVG_TIMER_WRITE: 31291284
MAX_TIMER_WRITE: 34952812
SUM_NUMBER_OF_BYTES_WRITE: 369
COUNT_MISC: 4
SUM_TIMER_MISC: 73923294676
MIN_TIMER_MISC: 251136
AVG_TIMER_MISC: 18480823560
MAX_TIMER_MISC: 73846656340
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