115 lines
5.5 KiB
Plaintext
115 lines
5.5 KiB
Plaintext
select OBJECT_INSTANCE_BEGIN from performance_schema.file_summary_by_instance limit 1
|
|
into @oib;
|
|
select FILE_NAME from performance_schema.file_summary_by_instance limit 1
|
|
into @fname;
|
|
select EVENT_NAME from performance_schema.file_summary_by_instance limit 1
|
|
into @ename;
|
|
|
|
====================================================================
|
|
Testing index for columns OBJECT_INSTANCE_BEGIN
|
|
====================================================================
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where OBJECT_INSTANCE_BEGIN = "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 COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where OBJECT_INSTANCE_BEGIN > "impossible";
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ALL PRIMARY NULL NULL NULL # 33.33 Using where
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where OBJECT_INSTANCE_BEGIN < "2";
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ALL PRIMARY NULL NULL NULL # 33.33 Using where
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where OBJECT_INSTANCE_BEGIN = @oib;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL const PRIMARY PRIMARY 8 const # 100.00 NULL
|
|
############# Explain End #########################################
|
|
flush status;
|
|
select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where OBJECT_INSTANCE_BEGIN = @oib;
|
|
COUNT(*)
|
|
#
|
|
OK: handler_read_key incremented
|
|
|
|
====================================================================
|
|
Testing index for columns FILE_NAME
|
|
====================================================================
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where FILE_NAME = "impossible";
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ref FILE_NAME FILE_NAME 2050 const # 100.00 NULL
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where FILE_NAME > "impossible";
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ALL FILE_NAME NULL NULL NULL # 33.33 Using where
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where FILE_NAME < "2";
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ALL FILE_NAME NULL NULL NULL # 33.33 Using where
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where FILE_NAME = @fname;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ref FILE_NAME FILE_NAME 2050 const # 100.00 NULL
|
|
############# Explain End #########################################
|
|
flush status;
|
|
select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where FILE_NAME = @fname;
|
|
COUNT(*)
|
|
#
|
|
OK: handler_read_key incremented
|
|
|
|
====================================================================
|
|
Testing index for columns EVENT_NAME
|
|
====================================================================
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where EVENT_NAME = "impossible";
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ref EVENT_NAME EVENT_NAME 514 const # 100.00 NULL
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where EVENT_NAME > "impossible";
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ALL EVENT_NAME NULL NULL NULL # 33.33 Using where
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where EVENT_NAME < "2";
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ALL EVENT_NAME NULL NULL NULL # 33.33 Using where
|
|
############ Explain for Query ####################################
|
|
explain select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where EVENT_NAME = @ename;
|
|
id select_type table partitions type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE file_summary_by_instance NULL ref EVENT_NAME EVENT_NAME 514 const # 100.00 NULL
|
|
############# Explain End #########################################
|
|
flush status;
|
|
select COUNT(*)
|
|
from performance_schema.file_summary_by_instance
|
|
where EVENT_NAME = @ename;
|
|
COUNT(*)
|
|
#
|
|
OK: handler_read_key incremented
|