不过，让其事务看到未提交的数据可以带来意料之外的副作用，如更新冲突和读取不一致等。

Letting uncommitted data be seen by other transactions, however, can result in unexpected side effects, such as clashing updates and inconsistent reads.

youdao

例如，如果一个成员正在更新一行数据，那么另一个成员就不能以未提交读(uncommitted read)以外的任何隔离级别读取这一行。

For example, if one member is updating a row, it would not be proper for another member to read the row with any other isolation level than uncommitted read.

youdao