Indeed, 'significant' depends on the environment and business needs. In
this case, he seemed more concerned about data loss, so max availability
may be worth looking into.
On Sunday, December 20, 2015, Mladen Gogala <gogala.mladen@xxxxxxxxx> wrote:
On 12/20/2015 04:39 PM, kathryn axelrod wrote:
Adding to what Andrew said, real time apply sends online log info..thisand maximum protection. Most of the places I've seen run in maximum
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
There is a significant performance penalty for both maximum availability
performance mode. The choice depends on the business needs.
--
Mladen Gogala
Oracle DBA
http://mgogala.freehostia.com
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