77 lines
3.7 KiB
Plaintext
77 lines
3.7 KiB
Plaintext
select OBJECT_INSTANCE_BEGIN, EVENT_NAME
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from performance_schema.socket_summary_by_instance
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limit 1
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into @oib, @e_name;
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====================================================================
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Testing index for columns OBJECT_INSTANCE_BEGIN
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====================================================================
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############ Explain for Query ####################################
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explain select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where OBJECT_INSTANCE_BEGIN = "impossible";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL # NULL no matching row in const table
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############ Explain for Query ####################################
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explain select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where OBJECT_INSTANCE_BEGIN > "impossible";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE socket_summary_by_instance NULL ALL PRIMARY NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where OBJECT_INSTANCE_BEGIN < "2";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE socket_summary_by_instance NULL ALL PRIMARY NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where OBJECT_INSTANCE_BEGIN = @oib;
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE socket_summary_by_instance NULL const PRIMARY PRIMARY 8 const # 100.00 NULL
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############# Explain End #########################################
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flush status;
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select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where OBJECT_INSTANCE_BEGIN = @oib;
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COUNT_STAR
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#
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OK: handler_read_key incremented
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====================================================================
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Testing index for columns EVENT_NAME
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====================================================================
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############ Explain for Query ####################################
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explain select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where EVENT_NAME = "impossible";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE socket_summary_by_instance NULL ref EVENT_NAME EVENT_NAME 514 const # 100.00 NULL
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############ Explain for Query ####################################
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explain select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where EVENT_NAME > "impossible";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE socket_summary_by_instance NULL ALL EVENT_NAME NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where EVENT_NAME < "2";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE socket_summary_by_instance NULL ALL EVENT_NAME NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where EVENT_NAME = @e_name;
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE socket_summary_by_instance NULL ref EVENT_NAME EVENT_NAME 514 const # 100.00 NULL
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############# Explain End #########################################
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flush status;
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select COUNT_STAR
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from performance_schema.socket_summary_by_instance
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where EVENT_NAME = @e_name;
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COUNT_STAR
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#
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OK: handler_read_key incremented
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