If you use XML predicates in the XMLQUERY function in the select clause of an SQL statement, these predicates do not eliminate any rows from the result set and therefore cannot use an index.

如果在sql语句的select子句的XMLQUERY函数中使用xml谓词，则这些谓词不会从结果集中排除任何行，因此不能使用索引。

youdao

If you use XML predicates in the XMLQUERY function in the select clause of an SQL statement, these predicates do not eliminate any rows from the result set and therefore cannot use an index.

如果在sql语句的select子句的XMLQUERY函数中使用xml谓词，则这些谓词不会从结果集中排除任何行，因此不能使用索引。

youdao