标签：column compute 崩溃 one rip eal tran 数值 receive
一般是用这个动态视图来查看 备库到主库的应用日志延迟时间。
首先解释下个字段的含义 NAME: apply lag:Amount of time that the application of redo data on the standby database lags behind the primary database.APPLY LAG- Apply lag is a measure of the degree to which the data in a standby database lags behind the data in the primary database,
due to delays in propagating and applying redo to the standby database.
This value is relevent only to the applying instance. （只与应用日志的实例有关，也就是 对于已经传到备库的redo来说，需要应用这部分redo日志需要的应用时间）
备库通过应用主库传过来的redo日志与主库同步所延迟的时间。 TRANSPORT LAG: How much redo data (in time units) generated by the primary database is not available or
applicable on the standby database at the time of computation。
没有传到备库的redo量或者在已经传输到备库但是备库没有应用的redo量。
APPLY FINISH TIME ：表示在备库上完成redo应用所需要的时间。
An estimate of the time needed to apply all received, but unapplied redo from the primary database.
（从主数据库已经接收到了，但是没有应用的重做日志 所需的时间估计。） ESTIMATED STARTUP TIME：启动和打开物理备库需要的时间，不适用逻辑备库 standby has been open,该值表示物理备库自从上次启动以来，是否以OPEN READ ONLY方式打开过？该参数值如果是Y，现在需要做FAILOVER，那么就需要先将该物理备库shutdown然后以OPEN READ WRITE方式打开。从第1个查询中，看到该物理备库如果做FAILOVER，那么就需要shutdown--->startup open read write；第2个查询中则没有该记录，因为11g的dataguard可以一边OPEN READ ONLY，一边执行redo apply,也就是11g 的ACTIVE Dataguard。 VALUE:参数的值 UNIT:各个参数的时间单元。 TIME_COMPUTED:物理备库上估算各个参数的本地时间 Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> select * from v$dataguard_stats; NAME VALUE -------------------- -------------------- UNIT ------------------------------------------------------------ TIME_COMPUTED DATUM_TIME -------------------- -------------------- transport lag +00 00:00:00 day(2) to second(0) interval 11/19/2014 03:04:55 11/19/2014 03:04:14 apply lag +00 00:57:25 day(2) to second(0) interval 11/19/2014 03:04:55 11/19/2014 03:04:14 NAME VALUE -------------------- -------------------- UNIT ------------------------------------------------------------ TIME_COMPUTED DATUM_TIME -------------------- -------------------- apply finish time +00 00:00:18.000 day(2) to second(3) interval 11/19/2014 03:04:55 该动态性能视图显示出在主库产生了多少重做日志数据，但是没有被备库所应用，所以通过该视图基本可以确定当主库崩溃的话，备库将丢失多少重做日志数据，同时我们可以估算failover的时间(apply finish time + estimated startup time).
官方原文：
V$DATAGUARD_STATS displays information about Oracle Data Guard metrics when queried on a standby database. No rows are returned when queried on a primary database.
| Column | Datatype | Description |
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Database ID of the protected source database |
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DB unique name of the protected source database |
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Name of the metric:
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Value of the metric |
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Unit of measurement |
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Local time at the standby database when the metric was computed |
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Local time at the standby database when the datum used to compute the metric was received The |
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The ID of the container to which the data pertains. Possible values include:
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标签：column compute 崩溃 one rip eal tran 数值 receive
原文地址：https://www.cnblogs.com/chendian0/p/12060406.html
