Performance Schema table_io_waits_summary_by_index_usage Table

The table_io_waits_summary_by_index_usage table records table I/O waits by index.

Column	Description
Column	Description
OBJECT_TYPE	TABLE in the case of all indexes.
OBJECT_SCHEMA	Schema name.
OBJECT_NAME	Table name.
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.

You can TRUNCATE the table, which will reset all counters to zero. The table is also truncated if the table_io_waits_summary_by_table 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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