select * from performance_schema.events_stages_summary_by_host_by_event_name
where event_name like 'stage/%' limit 1;
select * from performance_schema.events_stages_summary_by_host_by_event_name
where event_name='FOO';
insert into performance_schema.events_stages_summary_by_host_by_event_name
set event_name='FOO', thread_id=1,
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 'events_stages_summary_by_host_by_event_name'
update performance_schema.events_stages_summary_by_host_by_event_name
set count_star=12;
ERROR 42000: UPDATE command denied to user 'root'@'localhost' for table 'events_stages_summary_by_host_by_event_name'
update performance_schema.events_stages_summary_by_host_by_event_name
set count_star=12 where event_name like "FOO";
ERROR 42000: UPDATE command denied to user 'root'@'localhost' for table 'events_stages_summary_by_host_by_event_name'
delete from performance_schema.events_stages_summary_by_host_by_event_name
where count_star=1;
ERROR 42000: DELETE command denied to user 'root'@'localhost' for table 'events_stages_summary_by_host_by_event_name'
delete from performance_schema.events_stages_summary_by_host_by_event_name;
ERROR 42000: DELETE command denied to user 'root'@'localhost' for table 'events_stages_summary_by_host_by_event_name'
LOCK TABLES performance_schema.events_stages_summary_by_host_by_event_name READ;
ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_summary_by_host_by_event_name'
UNLOCK TABLES;
LOCK TABLES performance_schema.events_stages_summary_by_host_by_event_name WRITE;
ERROR 42000: SELECT, LOCK TABLES command denied to user 'root'@'localhost' for table 'events_stages_summary_by_host_by_event_name'
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='events_stages_summary_by_host_by_event_name';
column_name	column_comment
HOST	Host. Used together with EVENT_NAME for grouping events.
EVENT_NAME	Event name. Used together with HOST for grouping events.
COUNT_STAR	Number of summarized events, which includes all timed and untimed events.
SUM_TIMER_WAIT	Total wait time of the timed summarized events.
MIN_TIMER_WAIT	Minimum wait time of the timed summarized events.
AVG_TIMER_WAIT	Average wait time of the timed summarized events.
MAX_TIMER_WAIT	Maximum wait time of the timed summarized events.