237 lines
11 KiB
Plaintext
237 lines
11 KiB
Plaintext
# Connection con1
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create database explain_test_db;
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create table explain_test_db.explain_test_table(a int) engine = XENGINE;
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lock table explain_test_db.explain_test_table write;
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insert into explain_test_db.explain_test_table values (1);
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# Connection default
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select OBJECT_INSTANCE_BEGIN, OWNER_THREAD_ID, OWNER_EVENT_ID
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from performance_schema.table_handles
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where OBJECT_NAME = 'explain_test_table'
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into @oib, @o_tid, @o_eid;
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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(*)
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from performance_schema.table_handles
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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(*)
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from performance_schema.table_handles
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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 table_handles NULL ALL PRIMARY NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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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 table_handles NULL ALL PRIMARY NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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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 table_handles 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(*)
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from performance_schema.table_handles
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where OBJECT_INSTANCE_BEGIN = @oib;
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COUNT(*)
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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 OBJECT_TYPE, OBJECT_SCHEMA, OBJECT_NAME
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====================================================================
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 258 const # 100.00 NULL
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE > "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 table_handles NULL ALL OBJECT_TYPE NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE < "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 table_handles NULL ALL OBJECT_TYPE NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE";
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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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 258 const # 100.00 NULL
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "impossible"
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and OBJECT_SCHEMA = "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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 516 const,const # 100.00 NULL
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE"
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and OBJECT_SCHEMA = "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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 516 const,const # 100.00 NULL
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE"
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and OBJECT_SCHEMA > "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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 258 const # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE"
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and OBJECT_SCHEMA < "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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 258 const # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE"
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and OBJECT_SCHEMA = "explain_test_db";
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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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 516 const,const # 100.00 NULL
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "impossible"
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and OBJECT_SCHEMA = "impossible"
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and OBJECT_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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 774 const,const,const # 100.00 NULL
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE"
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and OBJECT_SCHEMA = "explain_test_db"
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and OBJECT_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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 774 const,const,const # 100.00 NULL
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE"
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and OBJECT_SCHEMA = "explain_test_db"
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and OBJECT_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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 516 const,const # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE"
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and OBJECT_SCHEMA = "explain_test_db"
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and OBJECT_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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 516 const,const # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE"
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and OBJECT_SCHEMA = "explain_test_db"
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and OBJECT_NAME = "explain_test_table";
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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 table_handles NULL ref OBJECT_TYPE OBJECT_TYPE 774 const,const,const # 100.00 NULL
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############# Explain End #########################################
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flush status;
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select COUNT(*)
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from performance_schema.table_handles
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where OBJECT_TYPE = "TABLE"
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and OBJECT_SCHEMA = "explain_test_db"
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and OBJECT_NAME = "explain_test_table";
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COUNT(*)
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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 OWNER_THREAD_ID, OWNER_EVENT_ID
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====================================================================
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID = "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 table_handles NULL ref OWNER_THREAD_ID OWNER_THREAD_ID 9 const # 100.00 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID > "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 table_handles NULL ALL OWNER_THREAD_ID NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID < "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 table_handles NULL ALL OWNER_THREAD_ID NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID = @o_tid;
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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 table_handles NULL ref OWNER_THREAD_ID OWNER_THREAD_ID 9 const # 100.00 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID = "impossible"
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and OWNER_EVENT_ID = "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 table_handles NULL ref OWNER_THREAD_ID OWNER_THREAD_ID 18 const,const # 100.00 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID = @o_tid
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and OWNER_EVENT_ID = "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 table_handles NULL ref OWNER_THREAD_ID OWNER_THREAD_ID 18 const,const # 100.00 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID = @o_tid
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and OWNER_EVENT_ID > "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 table_handles NULL ref OWNER_THREAD_ID OWNER_THREAD_ID 9 const # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID = @o_tid
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and OWNER_EVENT_ID < "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 table_handles NULL ref OWNER_THREAD_ID OWNER_THREAD_ID 9 const # 33.33 Using where
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############ Explain for Query ####################################
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explain select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID = @o_tid
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and OWNER_EVENT_ID = @o_eid;
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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 table_handles NULL ref OWNER_THREAD_ID OWNER_THREAD_ID 18 const,const # 100.00 Using where
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############# Explain End #########################################
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flush status;
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select COUNT(*)
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from performance_schema.table_handles
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where OWNER_THREAD_ID = @o_tid
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and OWNER_EVENT_ID = @o_eid;
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COUNT(*)
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#
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OK: handler_read_key incremented
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# Connection con1
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unlock tables;
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drop table explain_test_db.explain_test_table;
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drop database explain_test_db;
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# Connection default
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