如果有一个包含大量读取操作的工作负载，那么您可能想将隔离级别设置为未提交读取(UR)，从而不需要在每个语句中设置隔离级别。

If you have a read-heavy workload, you might want to set isolation to uncommitted read (UR) at the connection level so that you don't have to specify it in each statement.

youdao

在读事务中，没有变更需要提交，但是事务会防止对正在被读取的数据的修改，直到所有的读操作全部结束。

In a read transaction, there are no changes to commit, but the transaction prevents the data being read from changing until all of the reads are complete.

youdao

现在，读取事务可以访问当前提交的、连贯的行映像(写入事务以不兼容方式锁定)，而不会受到阻塞。

Now, a read transaction can access the currently committed and consistent image of rows that are incompatibly locked by write transactions without being blocked.

youdao