The Performance Schema file_summary_by_instance
table contains file events summarized by instance. As of MariaDB 10.0, 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. |
Before MariaDB 10, the table contained only the FILE_NAME
, EVENT_NAME
, COUNT_READ
, COUNT_WRITE
, SUM_NUMBER_OF_BYTES_READ
and SUM_NUMBER_OF_BYTES_WRITE
columns.
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.
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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Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/performance-schema-file_summary_by_instance-table/