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create user foo@localhost;
grant ALL on *.* to foo@localhost;
====================================================================
Testing index for columns HOST, ERROR_NUMBER
====================================================================
############ Explain for Query ####################################
explain select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST = "impossible";
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE events_errors_summary_by_host_by_error NULL ref HOST HOST 256 const # 100.00 NULL
############ Explain for Query ####################################
explain select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST > "impossible";
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE events_errors_summary_by_host_by_error NULL ALL HOST NULL NULL NULL # 33.33 Using where
############ Explain for Query ####################################
explain select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST < "2";
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE events_errors_summary_by_host_by_error NULL ALL HOST NULL NULL NULL # 33.33 Using where
############ Explain for Query ####################################
explain select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST = "localhost";
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE events_errors_summary_by_host_by_error NULL ref HOST HOST 256 const # 100.00 NULL
############ Explain for Query ####################################
explain select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST = "impossible"
and ERROR_NUMBER = "impossible";
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL # NULL no matching row in const table
############ Explain for Query ####################################
explain select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST = "localhost"
and ERROR_NUMBER = "impossible";
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL # NULL no matching row in const table
############ Explain for Query ####################################
explain select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST = "localhost"
and ERROR_NUMBER > "impossible";
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE events_errors_summary_by_host_by_error NULL ref HOST HOST 256 const # 33.33 Using where
############ Explain for Query ####################################
explain select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST = "localhost"
and ERROR_NUMBER < "2";
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE events_errors_summary_by_host_by_error NULL ref HOST HOST 256 const # 33.33 Using where
############ Explain for Query ####################################
explain select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST = "localhost"
and ERROR_NUMBER = "1146";
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
1 SIMPLE events_errors_summary_by_host_by_error NULL const HOST HOST 261 const,const # 100.00 NULL
############# Explain End #########################################
flush status;
select SUM_ERROR_RAISED
from performance_schema.events_errors_summary_by_host_by_error
where HOST = "localhost"
and ERROR_NUMBER = "1146";
SUM_ERROR_RAISED
#
OK: handler_read_key incremented
drop user foo@localhost;
|
