Re: archive_lag_target with real time apply for data guard
From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Sun, 20 Dec 2015 17:57:02 -0500
Message-ID: <5677323E.4070909_at_gmail.com>
On 12/20/2015 01:48 PM, max scalf wrote:
> Hello list,
>
> We are in process of setting up data guard and one of the thing i was
> thinking was to set "archive_lag_target" to 1800 seconds, so that i do
> not loose my redo data on the standby site if there was a failure on
> primary, but then it also got me thinking, I am using real time
> apply(this is specific to 11g system). From what i understand about
> real-time apply is "it allows Data Guard to recover redo data from the
> current standby redo log as it is being filled by the RFS process", if
> that is the case why would i need to set archive_lag_target as my data
> is being pushed out anyways ??
>
> thoughts ??
>
>
Hi Max!
Real-time apply is so-called "active data guard", which allows you to query the standby DB in read only mode. Very useful for reporting. Beware that loading data in GTT's does not work with the Active DG. Also, beware that active DG is not free, there is a license fee.
Date: Sun, 20 Dec 2015 17:57:02 -0500
Message-ID: <5677323E.4070909_at_gmail.com>
On 12/20/2015 01:48 PM, max scalf wrote:
> Hello list,
>
> We are in process of setting up data guard and one of the thing i was
> thinking was to set "archive_lag_target" to 1800 seconds, so that i do
> not loose my redo data on the standby site if there was a failure on
> primary, but then it also got me thinking, I am using real time
> apply(this is specific to 11g system). From what i understand about
> real-time apply is "it allows Data Guard to recover redo data from the
> current standby redo log as it is being filled by the RFS process", if
> that is the case why would i need to set archive_lag_target as my data
> is being pushed out anyways ??
>
> thoughts ??
>
>
Hi Max!
Real-time apply is so-called "active data guard", which allows you to query the standby DB in read only mode. Very useful for reporting. Beware that loading data in GTT's does not work with the Active DG. Also, beware that active DG is not free, there is a license fee.
-- Mladen Gogala Oracle DBA http://mgogala.freehostia.com -- http://www.freelists.org/webpage/oracle-lReceived on Sun Dec 20 2015 - 23:57:02 CET