40 lines
1.7 KiB
Plaintext
40 lines
1.7 KiB
Plaintext
create user foo@localhost;
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grant ALL on *.* to foo@localhost;
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====================================================================
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Testing index for columns HOST
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====================================================================
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############ Explain for Query ####################################
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explain select TOTAL_CONNECTIONS
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from performance_schema.hosts
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where HOST = "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 TOTAL_CONNECTIONS
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from performance_schema.hosts
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where HOST > "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 hosts NULL ALL HOST NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select TOTAL_CONNECTIONS
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from performance_schema.hosts
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where HOST < "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 hosts NULL ALL HOST NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select TOTAL_CONNECTIONS
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from performance_schema.hosts
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where HOST = "localhost";
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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 hosts NULL const HOST HOST 256 const # 100.00 NULL
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############# Explain End #########################################
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flush status;
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select TOTAL_CONNECTIONS
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from performance_schema.hosts
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where HOST = "localhost";
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TOTAL_CONNECTIONS
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#
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OK: handler_read_key incremented
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drop user foo@localhost;
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