2022-11-18 mysql-filesort-分析

摘要:

mysql-filesort-分析

参考:

https://zhuanlan.zhihu.com/p/311933050

MySQL :: MySQL 5.7 Reference Manual :: 8.2.1.14 ORDER BY Optimization

Use of filesort to Satisfy ORDER BY

If an index cannot be used to satisfy an ORDER BY clause, MySQL performs a filesort operation that reads table rows and sorts them. A filesort constitutes an extra sorting phase in query execution.

To obtain memory for filesort operations, the optimizer allocates a fixed amount of