database - 如何找到主备实例应用的日志序列的差距？

Question

如何从 RAC 环境中具有多个备用实例的主数据库中查找日志应用间隙？现在我正在使用下面的查询，但它给了我不正确的结果。

select sequenceInPrimary, sequenceSynchedInStandBy, sequenceInPrimary-sequenceSynchedInStandBy as logApplyGap from (select max(sequence#) sequenceInPrimary from v$archived_log) ,(select max(sequence#) sequenceSynchedInStandBy from v$archived_log where applied='YES')

Answer 1

我将此查询运行到我的 dataguard(19c)，结果正确。select sequenceInPrimary, sequenceSynchedInStandBy, sequenceInPrimary-sequenceSynchedInStandBy as logApplyGap from (select max(sequence#) sequenceInPrimary from v$archived_log) ,(select max(sequence#) sequenceSynchedInStandBy from v$archived_log where applied='YES')

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