Execution Plan Display is Incorrect

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This topic has been translated from a Chinese forum by GPT and might contain errors.

Original topic: 执行计划展示不对

| username: h5n1

Version: v6.1.1
The execution plan displayed for table joins is incorrect, and the explain time is relatively long.
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| username: Billmay表妹 | Original post link

This is probably because the NOT EXISTS subquery is a non-correlated simple subquery. Currently, TiDB will expand the calculation, and the result of NOT EXISTS is false, so it becomes a dual empty table.

This EXPLAIN result will consider optimization.

  • In the future, EXPLAIN should not take too much time, but how to optimize the dual output is still an open question.
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| username: h5n1 | Original post link

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