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To get the execution plan information that the specified thread is executing SQL, you can use the following statement

When it takes a long time for a thread to execute SQL, you can use this statement to find the execution plan that is executing a large SQL, which is useful in performance diagnosis.

Mysql > show processlist

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| | Id | User | Host | db | Command | Time | State | Info |

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| | 17 | root | localhost | NULL | Query | 0 | starting | show processlist | |

| | 18 | neo | localhost | fire | Query | 257 | Sending data | select count (*) from T1 join T2 on t1.a=t2.a |

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2 rows in set (0.00 sec)

Mysql > EXPLAIN FOR CONNECTION 18

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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 | T1 | NULL | index | idx_t1_a | idx_t1_a | 5 | NULL | 392945 | 100.00 | Using where; Using index |

| | 1 | SIMPLE | T2 | NULL | ref | idx_t2_a | idx_t2_a | 5 | fire.t1.a | 1 | 100.00 | Using index |

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2 rows in set (0.00 sec)

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