A quick warning:
When you setup a logical standby database, you need to activate supplemental logging on the primary database.
This is done automatically when you build the data dictionary (by running the dbms_logstdby.build procedure).
Activating supplemental logging is however (I know now) a control file change and is thus not replicated to the other physical standby databases.
As a result, the logical standby will become (logical) corrupt when you perform a role switch between your primary and another physical standby database.
I learned this the hard way :(
Luckily it was during a proof of concept and not in a real production environment … .
Of course, AFTERWARDS, I found the following maa document which points out that you have to enable supplemental logging yourself on the other physical standby databases.
It still makes a good read though
Oooh! Thanks for sharing. Thats a very useful tip.
Comment by prodlife — 20 October 2009 @ 23:32 |
Hi,
Learn by hard way is the one biggest experience.
Comment by dbametrix — 22 October 2009 @ 21:18 |
Yep, not likely I will forget this the next time :)
Comment by dhoogfr — 23 October 2009 @ 22:58 |
[…] Freek D’Hooge -Multiple standby databases and supplemental logging […]
Pingback by Blogroll Report 16/10/2009-23/10/2009 « Coskan’s Approach to Oracle — 27 October 2009 @ 1:55 |
Thanks! Made a small case in my mind to store and keep this information.
Comment by Bernard Polarski — 28 October 2009 @ 16:55 |