Performance Schema file_summary_by_instance Table

This table summarizes file I/O events aggregated by file instance, providing granular I/O statistics for individual files.

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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