Re: AWS capability question - Near 0 RPO options?

On 9/23/22 12:50, Tim Gorman wrote:
> Chris,
>
> Whether you're on-prem or in cloud...
>
> * RAC, RAC one-node, and OS-level HA clusters (i.e.
> Pacemaker/Corosync, etc) provide protection only to the /database
> //service/, not to the /data/ in the database/
> /
> o RPO isn't a factor with service protection, as RPO is a
> characteristic of /data protection//
> /
> * Restore/recovery from database backups can not guarantee RPO lower
> than the initialization parameter setting for ARCHIVE_LAG_TARGET
> o ...and there are many reasons to consider RPO to be at least
> twice the ARCHIVE_LAG_TARGET value as well...
> * Data replication utilities like GoldenGate, SharePlex, etc cannot
> guarantee RPO=0 due to all the queuing and forwarding necessary
> o "/eventual consistency/" also implies that "/eventual/" could
> turn out to be "/never/"
>
>
> The only Oracle mechanism which guarantees RPO=0 is DataGuard using
> MAX PROTECTION mode, while DataGuard in MAX AVAILABILITY mode comes in
> with a close second.
>
> Even the Zero Data Loss Recovery Appliance (ZDLRA) essentially employs
> the same mechanisms used by DataGuard MAX PROTECTION mode.
>
> Please let me know what you think?
>
> Thanks!
>
> -Tim

Vendors like EMC, Hitachi and NetApp claim that synchronous disk replication can guarantee zero data loss but I have never seen that in practice. I was a part of an attempt to do that using HUR ("Hitachi Universal Replicator") but we eventually settled for the maximum availability standby instead because the setup was just too complex. Tim, I fully agree with everything you said, this comment is just to touch on the subject of disk replication. I have never seen VMAX or something of that nature replace a standby database. Maybe cloud providers are using something like that? If there is an Oracle person familiar with the OCI infrastructure, I would love to hear some comments.

-- 
Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com

--
http://www.freelists.org/webpage/oracle-l