This table aggregates I/O wait statistics by index, helping to identify which indexes handle the most traffic or are causing latency.
The table_io_waits_summary_by_index_usage table records table I/O waits by index.
OBJECT_TYPE
TABLE in the case of all indexes.
OBJECT_SCHEMA
Schema name.
OBJECT_NAME
Table name.
You can the table, which will reset all counters to zero. The table is also truncated if the table is truncated.
If a table's index structure is changed, index statistics recorded in this table may also be reset.
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INDEX_NAME
Index name, or PRIMARY for the primary index, NULL for no index (inserts are counted in this case).
COUNT_STAR
Number of summarized events and the sum of the x_READ and x_WRITE columns.
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, and the sum of the equivalent x_FETCH columns.
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.
COUNT_WRITE
Number of all write operations, and the sum of the equivalent x_INSERT, x_UPDATE and x_DELETE columns.
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.
COUNT_FETCH
Number of all fetch operations.
SUM_TIMER_FETCH
Total wait time of all fetch operations that are timed.
MIN_TIMER_FETCH
Minimum wait time of all fetch operations that are timed.
AVG_TIMER_FETCH
Average wait time of all fetch operations that are timed.
MAX_TIMER_FETCH
Maximum wait time of all fetch operations that are timed.
COUNT_INSERT
Number of all insert operations.
SUM_TIMER_INSERT
Total wait time of all insert operations that are timed.
MIN_TIMER_INSERT
Minimum wait time of all insert operations that are timed.
AVG_TIMER_INSERT
Average wait time of all insert operations that are timed.
MAX_TIMER_INSERT
Maximum wait time of all insert operations that are timed.
COUNT_UPDATE
Number of all update operations.
SUM_TIMER_UPDATE
Total wait time of all update operations that are timed.
MIN_TIMER_UPDATE
Minimum wait time of all update operations that are timed.
AVG_TIMER_UPDATE
Average wait time of all update operations that are timed.
MAX_TIMER_UPDATE
Maximum wait time of all update operations that are timed.
COUNT_DELETE
Number of all delete operations.
SUM_TIMER_DELETE
Total wait time of all delete operations that are timed.
MIN_TIMER_DELETE
Minimum wait time of all delete operations that are timed.
AVG_TIMER_DELETE
Average wait time of all delete operations that are timed.
MAX_TIMER_DELETE
Maximum wait time of all delete operations that are timed.