让 MySQL 使用索引进行排序，但不在 WHERE 子句中？

Question

I have a query that simplifies to

SELECT *
FROM table
WHERE field > 5
ORDER BY field DESC

where field>5 matches more than half the records. I have an index on field , but MySQL isn't using it because too many records satisfy the condition. Is it possible to use the index only for the order, but not the WHERE clause?

Answer 1

I guess the simple answer is: there is no point in doing so, even if possible. The database optimizer decides when to use the index depending whether it's going to enhance the performance or not.