Adding to what Andrew said, real time apply sends online log info..this may
be sent anyway depending on other configs.
With max performance, it sends online log info when it's comitted on the
primary..but the primary pays no attention to when the standby applies it.
You may want to consider switching to max availability with at least one
standby using sync/affirm. It is a compromise between absolute 0 data loss
and no primary downtime with minimal primary waits.
With max availability, as long as a standby is available, it sends info to
the standby as soon as it's comitted to the primary's online log. (If no
standby is available, it temporarily switches to max performance so the
primary can continue).
With async/ noaffirm, the primary waits for the response that that standby
received the data. Sync/ affirm = wait to hear the standby Applied the data.
Alternately, with max protection, it is 0 data loss..but the primary may
shut down when it doesn't get a data confirmation from the standbys.
https://docs.oracle.com/database/121/SBYDB/protection.htm#SBYDB4743
On Sunday, December 20, 2015, max scalf <oracle.blog3@xxxxxxxxx> wrote:
Hi andrew,
so are you saying its okay to ignore that parameter on primary ?? as i am
using asynchronous(max perf mode) with real time apply ?
On Sun, Dec 20, 2015 at 1:09 PM, Andrew Kerber <andrew.kerber@xxxxxxxxx>
wrote:
As I understand the feature, it only applies to log switching. It was
probably named that when asynchronous data guard was more common. It really
only applies to recovery on the primary.
Sent from my iPad
On Dec 20, 2015, at 12:48 PM, max scalf <oracle.blog3@xxxxxxxxx> 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 ??
