select * from performance_schema.table_io_waits_summary_by_index_usage
limit 1;
select * from performance_schema.table_io_waits_summary_by_index_usage
where object_name='FOO';
insert into performance_schema.table_io_waits_summary_by_index_usage
set object_type='TABLE', object_name='FOO', object_schema='BAR',
count_star=1, sum_timer_wait=2, min_timer_wait=3,
avg_timer_wait=4, max_timer_wait=5;
ERROR 42000: INSERT command denied to user 'root'@'localhost' for table `performance_schema`.`table_io_waits_summary_by_index_usage`
update performance_schema.table_io_waits_summary_by_index_usage
set count_star=12;
ERROR 42000: UPDATE command denied to user 'root'@'localhost' for table `performance_schema`.`table_io_waits_summary_by_index_usage`
update performance_schema.table_io_waits_summary_by_index_usage
set count_star=12 where object_name like "FOO";
ERROR 42000: UPDATE command denied to user 'root'@'localhost' for table `performance_schema`.`table_io_waits_summary_by_index_usage`
delete from performance_schema.table_io_waits_summary_by_index_usage
where count_star=1;
ERROR 42000: DELETE command denied to user 'root'@'localhost' for table `performance_schema`.`table_io_waits_summary_by_index_usage`
delete from performance_schema.table_io_waits_summary_by_index_usage;
ERROR 42000: DELETE command denied to user 'root'@'localhost' for table `performance_schema`.`table_io_waits_summary_by_index_usage`
LOCK TABLES performance_schema.table_io_waits_summary_by_index_usage READ;
ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table `performance_schema`.`table_io_waits_summary_by_index_usage`
UNLOCK TABLES;
LOCK TABLES performance_schema.table_io_waits_summary_by_index_usage WRITE;
ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table `performance_schema`.`table_io_waits_summary_by_index_usage`
UNLOCK TABLES;
#
# MDEV-25325 column_comment for performance_schema tables
#
select column_name, column_comment 
from information_schema.columns 
where table_schema='performance_schema' and table_name='table_io_waits_summary_by_index_usage';
column_name	column_comment
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.
