unique_subquery

unique_subquery是一个索引查找函数，可以完全替换子查询，以提高效率。它适用于替换形式为"value IN (SELECT primary_key FROM single_table WHERE some_expr)"的子查询。这种替换可以减少查询时间，提高查询性能。引用还指出，unique_subquery可以替换形式为"value IN (SELECT primary_key FROM single_table WHERE some_expr)"的子查询，而index_subquery则适用于形式为"value IN (SELECT key_column FROM single_table WHERE some_expr)"的子查询，但只适用于非唯一索引。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
#### 引用[.reference_title]
- *1* [MySQL优化二之子查询](https://blog.csdn.net/youyou_yo/article/details/47400933)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT3_1"}}] [.reference_item style="max-width: 50%"]
- *2* *3* [mysql优化浅析](https://blog.csdn.net/youjie10231/article/details/71336265)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT3_1"}}] [.reference_item style="max-width: 50%"]
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