On 08/03/2016 11:23 AM, Tom Lane wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> I don't think they are saying that logical replication is more
>> reliable than physical replication, nor do I believe that to be true.
>> I think they are saying that if logical corruption happens, you can
>> fix it by typing SQL statements to UPDATE, INSERT, or DELETE the
>> affected rows, whereas if physical corruption happens, there's no
>> equally clear path to recovery.
>
> Well, that's not an entirely unreasonable point, but I dispute the
> implication that it makes recovery from corruption an easy thing to do.
> How are you going to know what SQL statements to issue? If the master
> database is changing 24x7, how are you going to keep up with that?
>
> I think the realistic answer if you suffer replication-induced corruption
> is usually going to be "re-clone that slave", and logical rep doesn't
> really offer much gain in that.
Yes, it actually does. The ability to unsubscribe a set of tables,
truncate them and then resubscribe them is vastly superior to having to
take a base backup.
JD
>
> regards, tom lane
>
>
--
Command Prompt, Inc. http://the.postgres.company/ +1-503-667-4564
PostgreSQL Centered full stack support, consulting and development.
Everyone appreciates your honesty, until you are honest with them.
Unless otherwise stated, opinions are my own.